GitLab stability issues

Since about a month or so we notice stability issues while using GitLab. Slow responses of the API with pipeliness taking a long time to be triggered and lately also persisting problems with loading the pipeline-status for merge requests. Are there any known issues that may be the cause of these troubles. We currently don’t have many developers switched to the managed service. We have our runners configured on a GCP kubernetes cluster (gitlab-runners) and the runners themselves do run normally.