Comment 3 for bug 1996459

I had this issue also. I was able to work around it by linking against the right library in pip, which is a nasty hack but it gets it working (and it has been almost a year):

pip install pyqt5==5.15.2
export LD_LIBRARY_PATH=/home/username/miniconda3/lib/python3.7/site-packages/PyQt5/Qt5/lib/