wifi connection issue

I'm facing an issue where my game doesn't connect properly over WiFi when I'm using a VPN. It works fine on mobile data with VPN, but as soon as I switch to WiFi, it fails to load or connect to servers.

I'm using a TP-Link router and have tried restarting both the VPN and router, but the problem persists. Could it be a port issue or DNS blocking by the router?

Also, for anyone curious, the game I'm referring to is available here. Appreciate any help or tips!