Collectible Card Game Headquarters

So i was trying some decks out a few days ago and today i wanted to play online with a friend, but because i have modded decks i cant play with anyone online, even if im not trying to use the custom decks. why is this?

All players in a match must have the exact same WADs with the exact same versions to be able to play together. If you want to play with someone while you have mods installed then they must have the exact same mods. If you want to play people without mods then you need to remove all the mods you put in.

I'm assuming since you're playing online this is the Steam version. Don't you risk them banning you for modifying the game?