Mac OS Big Sur 11.4 Matlab 2020b Python 3.8.10 compatibility

I upgraded to MacOS Big Sur 11.4 last night. I am running Python (version 3.8.10) modules from Matlab 2020b. Programs that were running yesterday now hang up on the importlib function (py.importlib.import_module). Commands to the standard Python library seem to work fine.

Anybody have any solutions?

Thanks