Grafana stuck on data/time


Grafana is stuck or only shows one date/time even the API is working.
Please see picture below.
I’m using PRTG and Grafana with Jason Lashua’s plugin and it was working yesterday without any problems.
Grafana v6.4.4 (092e514)
I have restarted Grafana and both server but no luck.

Any ideas why this might happen?

Thank you.

Does no one have an idea what might cause grafana not showing the data points?