I installed Python 3.6 on Ubuntu 16.04 by using Jonathon Fernyhough\'s PPA:
sudo add-apt-repository ppa:jonathonf/python-3.6 sudo apt-get update sudo apt-get
I removed python3-apt and that seems to have solved it for Python 3.8
python3-apt
sudo apt-get remove --purge python3-apt sudo apt-get install python3-apt