Cannot Manage DataSets: Debugging

How to debug following problem.
I have installed the AI Center. Did after installation checks, Created a project, created a dataset, upload a file.

The Next day. I see the project, I cannot manage Dataset.
I can create a project, but I cannot create a new dataset.
I can manage existing dataset (change description, and I see this on SQL database) but I cannot view or add files.
I can delete a dataset, but then table ai_trainer.datasets is empty.
Following error occuring:

I would be delighted to debug and investigate, but the question is: where to look.
I would think - SQL DB problem, if the updates of already existing dataset where not happening…

AI Center on prem with Centos7: Version 21.4.1
with MS SQL installed
[Orchestrator] 2020.10.7
UI Path [Studio]: 2020.10.2

Partial solution. Root Cause was in Proxy settings that changes (oh my oh my…)
kubectl set env deployment/kotsadm HTTP_PROXY=$http_proxy
kubectl set env deployment/kotsadm HTTPS_PROXY=$https_proxy
kubectl set env deployment/kotsadm NO_PROXY=$no_proxy

did the job. But still… where to look at logs?