The void function UButton::RebuildWidget() does not call PressMethod when rebuilding the widget.
Tested 4.19.2 (CL- 4033788), 4.20.3 (CL - 4369336), 4.21 (CL - 4537669), 4.22 (CL - 4531805)
Result: PressMethod is not being rebuilt.
Expected: PressMethod would be called when UButton::RebuildWidget() is called.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-66138 in the post.