Panels alternating between data / no data when refreshing

Hello,

we upgraded from grafana 6.5.0 to 7.0.3.

After the upgrade we have this picture:

  • some of the panels of the dashboard show a red exclamation mark with an error 404 page not found
  • at the next refresh of the dashboard, it may well be that there is data to be found in those same panels, but not in the panels which were showing data a moment ago
  • and this repeats itself

We use a prometheus service as a data source, backed by two prometheus pods (in Kubernetes).
We check the datasource Configuration > data sources > save & test: all green “Data source updated”, “Data source is working”.

Have you seen this problem before?

And

(as a new user I could not upload the third image in the same post)

Does the problem persist if you upgrade to the latest version of Grafana?