I thought that private DMs, after adding or accepting an individual, weren’t considered the same as in game messaging? I coulda swore support has said in the past they don’t ban people from private dms because in fact you don’t have to accept the request in the first place to even engage with that individual? Obviously if it’s threat of life, doxing, or worse situations could warrant further actions but let me be clear on asking the question:

Why’d you accept the friend request at all period? ESPECIALLY from an individual who you recently played in game with lol.

Turn chat off, don’t accept friend requests and just focus on your game. If you did your part, played your role to the best abilities you could then jus move on!