Error on client that connect to a remote ip

I’ve been playing around with multiplayer, But I’m getting error an when on clients that join the server (remotely, different country). The error doesnt happen right away, they can play for around 30 seconds before crashing out. this is the error:

The maps name is BPMPMAP, and the player pawn is BP_MP_Pawn.

Any reason why this would be happening, kinda new to multiplayer scripting.

thanks