I have a Flint 2 router connected to my home ISP provided router, the Flint 2 is acting as the WireGuard VPN Server.
I have A BerylAX travel router that is mobile tethered (Just to test) with a WireGuard client configured and connected to the Flint2 VPN Server fine. As per below.
Yes, the only thing I could think of was the mobile tethering/starlink part you mentioned but mine is tethered on the client side just to test? So this wouldn’t be causing the 0.00kb/s download speed would it?
Maybe the issue is on the server side. Is it working if you use phone app wireguard to connect?
Make sure the server interface has a network prefix other than 32.