I am experiencing the same problem (I think): Cannot direct connect to my friends and they cannot direct connect to me, BUT when I'm using my ExpressVPN connection, it actually works fine. If you have some fast VPN, you could try that. You could also try your mobile internet (with USB tethering or mobile hotspot) though that is probably not a solution you want to stick with.
Edit: I just noticed that this thread is in the DOS 2 forum. I am having these issues with BG3, but it might still be the same, who knows?
Last edited by GigaGrunch; 06/02/22 05:19 PM.