Created attachment 157121 [details]
Provides 2 examples and instructions to demonstrate the problem
The basic problem is that under certain circumstances, which I cannot explain fully, the "To Topline" command ("Up Arrow") is not able to continue to move the cursor upwards.
The attached file gives 2 test examples, with instructions about how to experience the problem. Have tested/confirmed the problem with 18.104.22.168 and 22.214.171.124.alpha, using the same file.
Not a serious hindrance, but have encountered this irritating issue from time to time (for many years now), so it would not be so bad if it evaporated somehow.
*** This bug has been marked as a duplicate of bug 118024 ***