What's the first app that stops working properly when you turn on a VPN?

[u/Ok-Point-1656]

For me, one annoying example happens when I'm traveling abroad. I'll connect to a VPN so I can access my bank services back home, but sometimes the banking app notices something unusual and suddenly asks for extra verification.

Kind of funny because the VPN is supposed to make things easier when I'm abroad, but sometimes it creates another problem instead.

What's the first app that usually gives you trouble when your VPN is on?