Playback doesn't reposition view in vertical scroll mode

1) Open attached score
2) Set Edit → Preferences… → Canvas → Scroll Pages to Vertically
3) Ensure Pan score automatically is active
4) Zoom the viewport so that the entire system no longer fits within it heightwise
5) Start playback

Expected result:
When the playback cursor moves "off screen", the viewport should reposition itself so the cursor remains in view.

Actual result:
Cursor moves "off screen", scoreview isn't repositioned.

6) Zoom out so the full system is now within the viewport
Scoreview now updates and follows score as expected

7) Zoom in again, so the full system no longer fits
Scoreview stops updating again