diff --git a/src/components/HOCs/WithCurrentTask/WithCurrentTask.jsx b/src/components/HOCs/WithCurrentTask/WithCurrentTask.jsx
index 8ed3ebb55..5420d7072 100644
--- a/src/components/HOCs/WithCurrentTask/WithCurrentTask.jsx
+++ b/src/components/HOCs/WithCurrentTask/WithCurrentTask.jsx
@@ -231,15 +231,20 @@ export const mapDispatchToProps = (dispatch, ownProps) => {
           // Wait for all parallel tasks to complete
           await Promise.all(parallelTasks);
 
-          // Handle next task loading - this needs to be sequential
+          // Handle next task loading - this needs to be sequential.
+          // challengeIdFromRoute falls back to props.challengeId, and ownProps
+          // carries one only when the route does (/challenge/:challengeId/task/
+          // :taskId). On the bare /task/:taskId route it doesn't, so seed it
+          // with the id the caller already handed us.
+          const nextTaskProps = { ...ownProps, challengeId };
           if (taskLoadBy) {
             // Start loading the next task from the challenge.
             const loadNextTask = Number.isFinite(requestedNextTask)
-              ? await nextRequestedTask(dispatch, ownProps, requestedNextTask)
-              : await nextRandomTask(dispatch, ownProps, taskId, taskLoadBy);
+              ? await nextRequestedTask(dispatch, nextTaskProps, requestedNextTask)
+              : await nextRandomTask(dispatch, nextTaskProps, taskId, taskLoadBy);
 
             try {
-              await visitNewTask(dispatch, ownProps, taskId, loadNextTask);
+              await visitNewTask(dispatch, nextTaskProps, taskId, loadNextTask);
             } catch (error) {
               ownProps.history.push(`/browse/challenges/${challengeId}`);
             }
@@ -287,13 +292,15 @@ export const mapDispatchToProps = (dispatch, ownProps) => {
         dispatch(addTaskComment(taskId, comment));
       }
 
+      // See completeTask above for why challengeId has to be seeded here
+      const nextTaskProps = { ...ownProps, challengeId };
       if (taskLoadBy === TaskLoadMethod.proximity && requestedNextTask) {
-        nextRequestedTask(dispatch, ownProps, requestedNextTask).then((newTask) =>
-          visitNewTask(dispatch, ownProps, taskId, newTask),
+        nextRequestedTask(dispatch, nextTaskProps, requestedNextTask).then((newTask) =>
+          visitNewTask(dispatch, nextTaskProps, taskId, newTask),
         );
       } else {
-        nextRandomTask(dispatch, ownProps, taskId, taskLoadBy).then((newTask) =>
-          visitNewTask(dispatch, ownProps, taskId, newTask),
+        nextRandomTask(dispatch, nextTaskProps, taskId, taskLoadBy).then((newTask) =>
+          visitNewTask(dispatch, nextTaskProps, taskId, newTask),
         );
       }
     },
diff --git a/src/components/TaskPane/TaskPane.jsx b/src/components/TaskPane/TaskPane.jsx
index a0da3f055..ac65a719b 100644
--- a/src/components/TaskPane/TaskPane.jsx
+++ b/src/components/TaskPane/TaskPane.jsx
@@ -605,9 +605,17 @@ export class TaskPane extends Component {
                 <Fragment>
                   <button
                     className="mr-button mr-button--white mr-mr-4"
-                    onClick={() =>
-                      this.props.history.push(`/task/${this.props.taskLockConflict.lockedTaskId}`)
-                    }
+                    onClick={() => {
+                      // Route through the challenge whenever we know it: on the
+                      // bare /task/:id route nothing supplies a challenge id,
+                      // and loading the next task after completion needs one
+                      const { lockedTaskId, parentId } = this.props.taskLockConflict;
+                      this.props.history.push(
+                        Number.isFinite(parentId)
+                          ? `/challenge/${parentId}/task/${lockedTaskId}`
+                          : `/task/${lockedTaskId}`,
+                      );
+                    }}
                   >
                     <FormattedMessage {...messages.goToLockedTaskLabel} />
                   </button>
diff --git a/src/services/Task/LockConflict.js b/src/services/Task/LockConflict.js
index 285369c15..a7f0a44a4 100644
--- a/src/services/Task/LockConflict.js
+++ b/src/services/Task/LockConflict.js
@@ -15,6 +15,7 @@ export const getLockConflict = (error) => {
 
   return {
     lockedTaskId: details.lockedTaskId,
+    parentId: typeof details.parentId === "number" ? details.parentId : null,
     parentName: details.parentName ?? null,
     bundledTasks: details.bundledTasks ?? [],
     startedAt: details.startedAt ?? null,
diff --git a/src/services/Task/LockConflict.test.js b/src/services/Task/LockConflict.test.js
index 5973737b1..5e7b889ed 100644
--- a/src/services/Task/LockConflict.test.js
+++ b/src/services/Task/LockConflict.test.js
@@ -22,6 +22,7 @@ describe("getLockConflict", () => {
       details: {
         message: "User 1 already holds a lock on item 123",
         lockedTaskId: 123,
+        parentId: 42,
         parentName: "Some Challenge",
         bundledTasks: [124, 125],
         startedAt: "2026-01-01T00:00:00Z",
@@ -30,6 +31,7 @@ describe("getLockConflict", () => {
 
     expect(getLockConflict(error)).toEqual({
       lockedTaskId: 123,
+      parentId: 42,
       parentName: "Some Challenge",
       bundledTasks: [124, 125],
       startedAt: "2026-01-01T00:00:00Z",
@@ -37,7 +39,7 @@ describe("getLockConflict", () => {
     });
   });
 
-  it("defaults parentName/bundledTasks/startedAt when absent", () => {
+  it("defaults parentId/parentName/bundledTasks/startedAt when absent", () => {
     const error = {
       response: { status: 409 },
       details: { message: "conflict", lockedTaskId: 123 },
@@ -45,6 +47,7 @@ describe("getLockConflict", () => {
 
     expect(getLockConflict(error)).toEqual({
       lockedTaskId: 123,
+      parentId: null,
       parentName: null,
       bundledTasks: [],
       startedAt: null,