Cant connect to a multiplayer game

I wanted to play Warzone but when I joined no players would come up in the search when searching for games. My internet connection was fine after checking . I tried some other game-modes ,still the same problem all online game-modes but the customs browser worked. I tried to play a Warzone game with one of my friends and he said that it came up with a message saying not all player suitable to play.
Is there anything I can do to fix my Game ?
Thanks

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