Connecting to Catalyst running inside a Docker container via Desktop Paraview

essentially I try to do an in-situ visualization of a fenics/dolfin simulation. At the moment I try to work on getting the pipeline correct in order to be able to simulate inside a docker container (later on singularity on an HPC) and visualize it live via Paraview. For this reason, I use the example scripts provided in the Paraview Catalysts Examples github repo.
Currently, the simulation and visualization work fine when I use my locally installed Paraview and Dolfin on my machine. I got a docker container with both paraview and dolfin installed and the sample scripts also work inside the container. My problem is, that I can’t connect via Catalyst to the simulation running inside the container. I try to make the port accessible outside the container using the -p 22222:22222 flag, but each time I try to access the simulation via Catalyst I get the error:

Socket error in call to bind.Address already in use.
Failed to set up server socket.

It seems like forwarding the ports in Docker blocks them for Catalyst, but I don’t know how to resolve the issue. Changing ports did not help.

Thank you for your help