I was just thinking that it might help to know what changed (maybe in wxwidgets as well?), as the things mentioned in wxPython 4.1.1 Released | wxPython doesn’t seem to be changes I would think of to break things.
Unfortunately, the answer is “a lot” because wxPython 4.1.x is based on wxWidgets main development branch.
wxPython 4.1.0 was based on wxWidgets commit e803408058186a7a9a61c456246f145abcaccd13.
wxPython 4.1.0 was based on wxWidgets commit 493cc3571e0308e1a273231daefa8deb7fbc4cf1.
So to get the real list of changes, you’d have to look at wxWidgets git repository and see what changed between those two commits.
Most likely these problems are due to some change/regression in wxWidgets. The best way to get those looked at is to file a ticket on Trac: https://trac.wxwidgets.org/. However, they will most likely ask for a way to reproduce the problem in C++ code.