Origin not allowed after upgrade to 9.1.6

Just upgraded Grafana from 8.2.5 → 9.1.6 and all my dashboards are complaining about an Origin not allowed error. I’m using Nginx 1.18 by the way.
Looking into community.grafana.com forum, found out several requests about this, and a fix seems to be adding proxy_set_header Host $http_host; into Nginx config file.
However in my case it doesn’t work, the same error still showing up.
Any ideas?

Haven’t found a fix for this yet…
Any ideas?