I have similar issue with grafana7 and traefikv2 , see in the picture 404 page not found , which appear randomly when dashboard refresh. Initially I though that was a problem with traefik v2, since I have grafana v6.xx with traefik v1.7 running without that kind of problem.
But now I tried grafana 7 with traefik v1.7 and I got the same issue, so looks like the problem is grafana 7.
I have to try Grafana 6 with traefik v2 to make sure the problem is with grafana7 Not with traefik v2.
