Buttons no longercompatible with old Mac versions?

[MISV]

I got an error report:

Version 11.x of my software = buttons clicking work
Version 12.x of my software do not work reliably on MacOS Sierra, but do work on Mac M1 (so supposedly much newer MacOS)
On my own Mac computer using BigSur most clicking works.

My own code is not changed a lot (not at all with regards to UI), so I would suspect it is some change in Cocoa LCL?

I originally targeted 10.8, and the app runs, so I suspect that part is working.

Can anyone confirm this? Maybe someone know if some code changed? Otherwise maybe I will just close my eyes until I get more bug reports.

[wp]

Not sure if this is related, but when I still had the VM with Mojave, I had compilation problems and was advised to do this:

- open /etc/fpc.cfg, activate the define "DisableCocoaModernForms" (last line), save
- in the Lazarus directory do a "make clean bigide"
- I still had issues in line "initIDECocoaConfigForms" in ide/main.pp --> commented it out, repeat "make clean bigide".
- Afterwards the IDE was usable.
- Go to "Tools" > "Build Lazarus with profile" to rebuild the IDE a last time, now with your installed components.