I'm running docker on Ubuntu and ran into this issue the other day where I could run new containers or even see the current ones running... Very frustrated because I knew they were running as the website was still up and responsive. I did get the idea of if I had two installations of Docker...
To check if you have two installations of docker
snap list | grep docker
dpkg --list | grep docker
Which showed me I had a snap installation too
sudo snap remove docker
Got rid of the puppy after it took time to unistall and restarted the services again
sudo systemctl restart docker.service docker.socket