if your using a reverse proxy, then i have found that if you use the address you set up in that it works just fine, i had to do the same thing, though i am using it to access the unraid-ui as well, so if you have "unraid.yourproxiedaddress.com" to access your unraid, then that is the address you would need to use for your base url in the grafana panel's settings, not an ip address, i believe it has to do with internal translations of ip's to dns.