ChristianStrangholt

That topic specifically was related to the R1 so I don't think that will apply here. Set NAT to Open in WAN Settings and disable the protection options on that page as well and see if it works.

Yes, I'll try later

Thanks for that, I'll pass this onto the team, it may be the Adblocker then, if you disable that does it work?

So two possibilities:
You're blocking each other with the Geo-Filter You're blocking the Discord servers with the Geo-Filter Either way you'll need to do some allowing, you can see how to do so at the bottom of this guide: https://support.netduma.com/en/support/solutions/articles/16000077072-dumaos-optimal-settings-guide-geo-filter 
If you're not blocking each other/you have each other allowed and it's not working then try to join Discord and look on the map for a blocked server, then add it to the allow list in the same way and you should be able to join each other properly. It might take a few tries if there are multiple servers to get them all allowed.
Any Discord servers you come across that need to be allowed, if you provide us with the IDs we can get them added to the whitelist.

I'll add you to the list!

I'll add your name to the list!