Error on cloning a git project

Hi,
I have on my vServer a docker container with GitLab. I can login via web interface and on my PC (Kubuntu) can I push and commit my project. I did a new installation with Kubuntu on my laptop and here I will get the following error “The requested URL returned error: 500” If I clone my Git project. I don’t knwo where the problem is. Do you have a tip where the problem is?

Today I did an upgrade from GitLab 16.10 to 17.5.2, according to the update instructions. I can access via web interface my GitLab repository, but I can’t clone any projects on my laptop with the https address.

How can I solve the problem?

Thank you for your help.
BR
martin