Docker daemon suddenly shut down

we just encountered an extremely strange bug over the last few days. We have a bunch of linux servers (Ubuntu 20.04.1 LTS) that run a couple of docker containers (version 19.03.8) using docker-compose (version 1.25.4). These were running well for the last 1-2 months, and then all of a sudden the last few days, the containers have been dropping like flies. All docker commands (even a docker ps), don’t work, and we get an exception about how the servers cannot connect to the docker daemon. The fix is to either reboot the server or start the docker service again, but does anyone know why this is happening?