After Excel January 2023 update VBA Macro not working

I have an excel spreadsheet with lots of macro buttons. It's been working perfectly for years.
I have recently updated excel (Jan 2023) and now the most important button is not working properly.
I have spent days trying to fix it and am hoping that my findings/partial solution below can give someone a clue of what is the issue.

1) When I load the file it does not work.
2) I then open the code behind the macro button and change 1 thing. (Userform_Initialize to Userform_Activate)
3) Then everything works fine, so I save the file
4) When I re-open the newly saved file, I try and run the macro and the macro has the same problem.

I am scratching my head over this. It seems like the only way to make the macro work is to edit the code of the original file every time I open it. But it doesn't work every time. I have to keep trying until it works.

I have also noticed that when I do get the file to work, if I change the vba code back to it's original state, it works!

I hope someone can help

Thanks

Tom

I'd suggest you put your workbook up as a first step to getting a solution.