Hi! I think your problems with the latest version of the opencv-contrib-python can be related to changes in tracking API:
I tried to use Win10, Python 3.8.5, opencv-contrib-python==4.4.0.46, and all works fine.
Please, use the 4.4.0.46 version for now and keep watching for changes in tracking API:
and changes of opencv-python:
Also, the pip show open-contrib-python command should work, instead of pip3 show opencv.