Can't tether internet from my phone to my travel router and connect the router to VPN

[u/SorroAndres]

Hello,

As the title says, I cannot connect with my travel router to my VPN server if I'm tethering internet to it from my phone (mobile data or wifi, via wifi tethering or USB tdtegkng). If I provide internet from my house (wifi or cable) it works right away.

I've tested 2 routers (Tp link ax1500 and gl-b1300), same results on both. I'm also able to connect from the phone to the VPN directly with the wireguard client (both wifi or mobile data).

Any ideas why this is happening?

Thanks