Firefox plugin not working

For some reason, on my 2 computers if i run the VPN plugin from FireFox, it says it is connected, but no webpage works. If i use the full app to connect it works just fine.

I tried to restart FF. I logged in and out of ProtonVPN via the plugin. I made sure that there were no updates to ProtonVPN plugin. nothing works. I tried different servers in different countries (either using quick connect, or manually selecting something in my own country, or another). Nothing works.

I did rebuild my firewall tonight, but not sure if that would have caused anything. I can browse normally without the plugin, or i can browse just fine using the full app. When i rebuilt the firewall, i manually entered all the ports I had before and everything else I have seems to be working.

edit: if i enable secure core then it works.

For me the issue was network.trr.mode. Proton mentions this should be set to 3, however this causes Firefox to be unable to connect (for me). Setting it to 5 fixes it, and I have no DNS leaks. Don’t know if this is the same for your.

Where do I find that option?

about:config -> network.trr.mode