Handling internet stops

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Hey guys, I'm using photon PUN to run a 2d platformer race game.
The game has weapons that work in a certain radius.

Now I'm trying to think, what would happen if a player is on his phone at the train and enters a tunnel for 8~10 seconds..
He will temporarily lose connection, not be getting RPCs from other player's weapon casts, so he'll just pause at everyone's phones, but when he comes out of the tunnel, he's player will be a lot ahead without facing any weapon casts (like he's god mode).

How can I address these internet issues and keep the game fair?

Is there an option to locally block movement for clients who didn't respond to packets after certain amount of time or something like that?

Thanks :)