Dashboard import from 6 to 7 gives 403 due to lines limit?

Hi,

My Grafana is a fresh installation and is accessed via an nginx webserver (just as version 6x was)
To reach it I go via an ssh tunnel. The servername is set to 127.0.0.1 in my local hosts file (nginx is running namebased virtualhosts and there are multiple websites running in there)

Am trying to get a dashboard from Grafana 6.3.3 imported in Grafana 7.7.1

This does not work and gives a 403 error with some html bahblah in a red errorbox in the upprright corner of the window.

The concerning log lines in grafana:

t=2020-09-02T15:22:00+0200 lvl=eror msg="Dashboard not found" logger=context userId=1 orgId=1 uname=admin error="Dashboard not found" remote_addr=127.0.0.1
t=2020-09-02T15:22:00+0200 lvl=info msg="Request Completed" logger=context userId=1 orgId=1 uname=admin method=GET path=/api/dashboards/uid/2ahNSqJmk status=404 remote_addr=127.0.0.1 time_ms=0 size=33 referer=https://adcdashboard.ora.prd.itv.local:4433/dashboard/import

The dashboard is too large to paste the json here otherwise I would have done so.

Is grafana assuming it is the default host on 127.0.0.1? If not, what else could be going wrong here?

To continue anyway I created an empty dashboard in grafana and started to copy paste each panel separately to see what happens. Hwat I found out is that I can copy 4 panels ok. From the fifth on every panel gives the error as wel as soon as I want to save the json (in dashboard settings, that is). But if I delete one of the first 4, I can without issue paste one of the oters over there and save.

So appaerantly the is some restriction in Grafana 7 that wasn’t there in 6, either in Nr. of lines thet can be posted or Nr. of panels or something like that?

Anyone knows?

Edit: ok… The same dashboard DID exist on mij acc. environment. So I took the jason of that (version 7) grafana and still bump into the same problem.