I got banned from playing for 5 min, after i found a match while loading into watch friend's game

[palmcsgo]

normally it take 10-20 min for my account to find 1 match, so i'll watch game while waiting for game. But this time, i found a match while the game that i want to watch is loading, then i got banned.
I think this is mistake, will it affect my behavior score or mmr?

this is account that this happened: https://steamcommunity.com/profiles/76561198983945849/

 

[Nicoji]

I think this is kind of the same bug as entering Hero Sandbox at the moment a match is found.
Until it is solved you'd be best alt-tab and do something else while waiting for a match...