I dunno if this had anything to do with it but there is peer to peer online gaming with Divinity Original Sin 2, and I tried grouping up with many folks I friended online and not in the same time zone and it never worked for us. Borderlands also appears to use peer to peer connections.

Yeah this is what I thought, I remember fiddling around with this to make Soulseek (or something) work on my old Linksys WRT54G back when I was at university. I wonder what Switch services/games work this way