@ronaldoussoren In my case it was not Outlook, it was a third party line of business application,
but as in the case of the OP, as mentioned in the StackOverflow link, the crashing only happens using certain Python version.

I'm not suggesting the issue of the OP (nor mine) is in CPython.  But it's strange at least that it depends on the Python version, and that it does not crash when using the REPL (I did try to compensate for delays etc.).

I took the PyQt route to 'proof' the issue is not related to pywin32.

When running it in a debugger, the crash happens in an MFC dll, after the Invoke of the COM method.

So my guess is the issue is related to some incompatibility in MSVC libraries between CPython and the line of business application.