diff --git a/backend/plugins/github/e2e/pr_convertor_incremental_test.go b/backend/plugins/github/e2e/pr_convertor_incremental_test.go
new file mode 100644
index 00000000000..38f72be93cd
--- /dev/null
+++ b/backend/plugins/github/e2e/pr_convertor_incremental_test.go
@@ -0,0 +1,167 @@
+/*
+Licensed to the Apache Software Foundation (ASF) under one or more
+contributor license agreements.  See the NOTICE file distributed with
+this work for additional information regarding copyright ownership.
+The ASF licenses this file to You under the Apache License, Version 2.0
+(the "License"); you may not use this file except in compliance with
+the License.  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package e2e
+
+import (
+	"context"
+	"sort"
+	"testing"
+	"time"
+
+	"github.com/apache/devlake/core/dal"
+	coreModels "github.com/apache/devlake/core/models"
+	"github.com/apache/devlake/core/models/domainlayer/code"
+	"github.com/apache/devlake/core/plugin"
+	"github.com/apache/devlake/core/runner"
+	"github.com/apache/devlake/core/utils"
+	"github.com/apache/devlake/helpers/e2ehelper"
+	contextimpl "github.com/apache/devlake/impls/context"
+	"github.com/apache/devlake/plugins/github/impl"
+	"github.com/apache/devlake/plugins/github/models"
+	"github.com/apache/devlake/plugins/github/tasks"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// runSubtaskIncrementally executes one subtask with the subtask state left in place and a
+// sync policy that permits incremental mode, which DataFlowTester.Subtask cannot do: it
+// flushes _devlake_subtask_state and forces FullSync on every call
+// (helpers/e2ehelper/data_flow_tester.go). Same approach as
+// plugins/youtrack/e2e/stateful_scenario_test.go, with the subtask and plugin names passed
+// in their own positions so the state key matches the one the subtask itself computes.
+func runSubtaskIncrementally(
+	t *testing.T,
+	dataflowTester *e2ehelper.DataFlowTester,
+	subtaskMeta plugin.SubTaskMeta,
+	taskData interface{},
+) {
+	t.Helper()
+	subtaskCtx := contextimpl.NewStandaloneSubTaskContext(
+		context.Background(),
+		runner.CreateBasicRes(dataflowTester.Cfg, dataflowTester.Log, dataflowTester.Db),
+		subtaskMeta.Name,
+		taskData,
+		dataflowTester.Name,
+		&coreModels.SyncPolicy{},
+	)
+	require.NoError(t, subtaskMeta.EntryPoint(subtaskCtx))
+}
+
+// TestGithubPrConvertorIncremental covers the incremental filter of "Convert Pull Requests".
+//
+// `stateManager.GetSince()` is the start time of the previous successful run of the subtask
+// (`_devlake_subtask_state.prev_started_at`), so the filter has to select the tool records
+// DevLake wrote since then, i.e. the ones whose own `updated_at` is at or after it.
+//
+// Pull request 29 is the regression guard: GitHub last touched it in 2019, DevLake rewrote
+// its row after the previous run (`state` and `merged` were corrected), and the domain record
+// still has to be updated. Filtering on `github_updated_at` compared that 2019 timestamp
+// against a 2026 run time and skipped the record on this run and on every run after it, which
+// left the domain record missing or stuck on its old status (#9150).
+func TestGithubPrConvertorIncremental(t *testing.T) {
+	var githubPlugin impl.Github
+	dataflowTester := e2ehelper.NewDataFlowTester(t, "github", githubPlugin)
+
+	taskData := &tasks.GithubTaskData{
+		Options: &tasks.GithubOptions{
+			ConnectionId: 1,
+			Name:         "panjf2000/ants",
+			GithubId:     134018330,
+		},
+	}
+
+	prevStartedAt := time.Date(2026, 9, 16, 16, 24, 0, 0, time.UTC)
+	// GitHub's timestamp for pull request 29, older than every DevLake run.
+	collectedLongAgo := time.Date(2019, 8, 8, 8, 31, 19, 0, time.UTC)
+	writtenAfterPrevRun := time.Date(2026, 9, 17, 10, 0, 0, 0, time.UTC)
+	writtenBeforePrevRun := time.Date(2026, 9, 15, 10, 0, 0, 0, time.UTC)
+
+	dataflowTester.FlushTabler(&models.GithubPullRequest{})
+	dataflowTester.FlushTabler(&code.PullRequest{})
+	dataflowTester.FlushTabler(&coreModels.SubtaskState{})
+
+	// A pull request GitHub last updated in 2019 whose row DevLake rewrote after the previous
+	// run, one updated on GitHub after the previous run, and one untouched since before it.
+	seedPullRequest(t, dataflowTester, 101, 29, "closed", true, collectedLongAgo, writtenAfterPrevRun)
+	seedPullRequest(t, dataflowTester, 102, 30, "closed", true, writtenAfterPrevRun, writtenAfterPrevRun)
+	seedPullRequest(t, dataflowTester, 103, 31, "open", false, writtenBeforePrevRun, writtenBeforePrevRun)
+
+	// Previous successful run of this subtask. PrevConfig is left empty so the subtask is not
+	// treated as reconfigured, which would force full sync.
+	require.NoError(t, dataflowTester.Dal.CreateOrUpdate(&coreModels.SubtaskState{
+		Plugin:        "github",
+		Subtask:       tasks.ConvertPullRequestsMeta.Name,
+		Params:        utils.ToJsonString(tasks.GithubApiParams{ConnectionId: 1, Name: "panjf2000/ants"}),
+		PrevStartedAt: &prevStartedAt,
+	}))
+
+	runSubtaskIncrementally(t, dataflowTester, tasks.ConvertPullRequestsMeta, taskData)
+
+	var domainPullRequests []code.PullRequest
+	require.NoError(t, dataflowTester.Dal.All(&domainPullRequests))
+	converted := make([]int, len(domainPullRequests))
+	statuses := map[int]string{}
+	for i, domainPullRequest := range domainPullRequests {
+		converted[i] = domainPullRequest.PullRequestKey
+		statuses[domainPullRequest.PullRequestKey] = domainPullRequest.Status
+	}
+	sort.Ints(converted)
+
+	assert.Equal(t, []int{
+		29, // rewritten by DevLake after the previous run, last updated on GitHub in 2019
+		30, // updated on GitHub after the previous run
+	}, converted)
+	assert.Equal(t, code.MERGED, statuses[29], "the corrected status has to reach the domain layer")
+	assert.NotContains(t, converted, 31, "records untouched since before the previous run must be skipped")
+}
+
+// seedPullRequest inserts a tool-layer pull request and then forces `updated_at`, which gorm
+// would otherwise set to the time of the insert.
+func seedPullRequest(
+	t *testing.T,
+	dataflowTester *e2ehelper.DataFlowTester,
+	githubId int,
+	number int,
+	state string,
+	merged bool,
+	githubUpdatedAt time.Time,
+	updatedAt time.Time,
+) {
+	t.Helper()
+	pullRequest := &models.GithubPullRequest{
+		ConnectionId:    1,
+		GithubId:        githubId,
+		RepoId:          134018330,
+		Number:          number,
+		State:           state,
+		Merged:          merged,
+		GithubCreatedAt: githubUpdatedAt,
+		GithubUpdatedAt: githubUpdatedAt,
+	}
+	if merged {
+		pullRequest.MergedAt = &githubUpdatedAt
+		pullRequest.ClosedAt = &githubUpdatedAt
+	}
+	require.NoError(t, dataflowTester.Dal.CreateOrUpdate(pullRequest))
+	require.NoError(t, dataflowTester.Dal.UpdateColumn(
+		&models.GithubPullRequest{},
+		"updated_at",
+		updatedAt,
+		dal.Where("connection_id = ? AND github_id = ?", 1, githubId),
+	))
+}
diff --git a/backend/plugins/github/tasks/cicd_run_convertor.go b/backend/plugins/github/tasks/cicd_run_convertor.go
index 62f6a355a4f..48876a58562 100644
--- a/backend/plugins/github/tasks/cicd_run_convertor.go
+++ b/backend/plugins/github/tasks/cicd_run_convertor.go
@@ -83,7 +83,7 @@ func ConvertRuns(taskCtx plugin.SubTaskContext) errors.Error {
 			if stateManager.IsIncremental() {
 				since := stateManager.GetSince()
 				if since != nil {
-					clauses = append(clauses, dal.Where("github_updated_at >= ?", since))
+					clauses = append(clauses, dal.Where("updated_at >= ?", since))
 				}
 			}
 			return db.Cursor(clauses...)
diff --git a/backend/plugins/github/tasks/issue_comment_convertor.go b/backend/plugins/github/tasks/issue_comment_convertor.go
index 80180b3e015..43c9747420b 100644
--- a/backend/plugins/github/tasks/issue_comment_convertor.go
+++ b/backend/plugins/github/tasks/issue_comment_convertor.go
@@ -73,7 +73,7 @@ func ConvertIssueComments(taskCtx plugin.SubTaskContext) errors.Error {
 			if stateManager.IsIncremental() {
 				since := stateManager.GetSince()
 				if since != nil {
-					clauses = append(clauses, dal.Where("_tool_github_issue_comments.github_updated_at >= ?", since))
+					clauses = append(clauses, dal.Where("_tool_github_issue_comments.updated_at >= ?", since))
 				}
 			}
 			return db.Cursor(clauses...)
diff --git a/backend/plugins/github/tasks/issue_convertor.go b/backend/plugins/github/tasks/issue_convertor.go
index 8184c1343b1..7adef674089 100644
--- a/backend/plugins/github/tasks/issue_convertor.go
+++ b/backend/plugins/github/tasks/issue_convertor.go
@@ -88,7 +88,7 @@ func ConvertIssues(taskCtx plugin.SubTaskContext) errors.Error {
 			if stateManager.IsIncremental() {
 				since := stateManager.GetSince()
 				if since != nil {
-					clauses = append(clauses, dal.Where("github_updated_at >= ?", since))
+					clauses = append(clauses, dal.Where("updated_at >= ?", since))
 				}
 			}
 			return db.Cursor(clauses...)
diff --git a/backend/plugins/github/tasks/pr_comment_convertor.go b/backend/plugins/github/tasks/pr_comment_convertor.go
index 23c29e123a9..30e57f84df9 100644
--- a/backend/plugins/github/tasks/pr_comment_convertor.go
+++ b/backend/plugins/github/tasks/pr_comment_convertor.go
@@ -76,7 +76,7 @@ func ConvertPullRequestComments(taskCtx plugin.SubTaskContext) errors.Error {
 			if stateManager.IsIncremental() {
 				since := stateManager.GetSince()
 				if since != nil {
-					clauses = append(clauses, dal.Where("_tool_github_pull_request_comments.github_updated_at >= ?", since))
+					clauses = append(clauses, dal.Where("_tool_github_pull_request_comments.updated_at >= ?", since))
 				}
 			}
 			return db.Cursor(clauses...)
diff --git a/backend/plugins/github/tasks/pr_convertor.go b/backend/plugins/github/tasks/pr_convertor.go
index 3b39aca77ae..b5b1a01078e 100644
--- a/backend/plugins/github/tasks/pr_convertor.go
+++ b/backend/plugins/github/tasks/pr_convertor.go
@@ -72,7 +72,11 @@ func ConvertPullRequests(taskCtx plugin.SubTaskContext) errors.Error {
 			if stateManager.IsIncremental() {
 				since := stateManager.GetSince()
 				if since != nil {
-					clauses = append(clauses, dal.Where("github_updated_at >= ?", since))
+					// `since` is when the previous run of this subtask started, so the filter has to
+					// select the records DevLake wrote after it, not the ones GitHub changed after it:
+					// a record whose `github_updated_at` is older than `since` still has to be
+					// converted when a later collection rewrote it.
+					clauses = append(clauses, dal.Where("updated_at >= ?", since))
 				}
 			}
 			return db.Cursor(clauses...)