High internet speed doesn't necessarily mean that the connection is stable. The fact that you have no problem with other games is not very important, because most games don't make it apparent if you lose connectivity for one second, while in Toribash it can be enough to ping you out of the room.
It is almost certain that one of your hardware components is faulty or weak, whether that would be your router, laptop, or simply a little conflict between both. Resetting your router settings to default is always a good idea unless you got something special going on, also make sure there are no metal or large objects between your laptop and router (this could be very probable cause of your issue).
There is quite a simple way to tell if it's faulty Wi-Fi or is it any other issue. Plug your Laptop to router via ethernet cable, play Toribash for some time, and see if you ping or not. If you do ping with a cable then it's something different and I'm completely wrong, but if you don't ping, you will know that it's the Wi-Fi problem and you can look for sollutions from there.