My mom changed our internet service provider and now multiplayer doesn't work with steam games

[Carolus Rex]

So for context our home wifi is absolute ♥♥♥♥♥♥♥ so I use my hotspot on my phone to have internet on my pc, and mostly it works decently. My mom decided to change our internet service provider and now for whatever reason playing multiplayer games such as CS2 or terraria just doesn't work. On cs I can enter the game and join friends but not enter a match, and in terraria I can't even join my friends. This also only seems to be happening with steam games, as I can play Overwatch just fine without any issues. Anyone got a solution? Thanks!

[Iceira]

Should you not have this talk with mom, what new ISP have done this, and what your mom know about it, we cant open the traffic for you, thats your mom ISP.

[nullable]

New ISP probably means new router, new router might mean you need additional firewall rules to open up game specific ports. the ISP may have some help documentation about that since it would be a common issue.

This might also be handy, https://help.steampowered.com/en/faqs/view/2EA8-4D75-DA21-31EB individual games have have their own ports as well.