If someone has experienced the same problem please help:
I’m using a raspberry pi 4 with a 32 gb sd card and running ubuntu 20.04 64bit.
Just running the original container of nginx alpine.
After some time running the node is offline, and when accessing it via ssh the docker stopped with the following error:
ubuntu @ rb-worker-01: ~ $ docker ps
Cannot connect to the Docker daemon at unix: ///var/run/docker.sock. Is the docker daemon running?
I think an important detail is that it still works in the manager, which is also a raspberry pi 4, but with 8gb ram and with a 16 gb sd card from another brand. in the manager it runs without problems.