So, basically: I queued for a competitive match but was tabbed out while waiting. When I heard the sound of a game being found, I tabbed back into the game. Yet when I was expecting to be in a match, I was still on the main menu of overwatch. I tried to click “rejoin game” but nothing happened. When I tried to restart my game I found out I was suspended.
How/why did this happen? I know that my internet isn’t the problem. Now I lost SR and got suspended for 10 minutes (it isn’t that long, but it still sucks cause I was hyped to play a match) 
This isn’t a bug and is the intended behavior for leaver penalties. I recommend reading over: Overwatch Technical Issues, SR Loss, and Leaver Penalties
It could have been a small hiccup in your connection. Overwatch requires a very steady connection with almost zero packet loss to function properly.
You should also edit and move your post to #technical-support
Sorry for the late reaction, I didn’t really check on my post.
I understand that getting suspended for leaving is not a bug, but my problem was that I was never put in the match in the first place. I didn’t leave, I didn’t get disconnected, the game just told me that it found a match yet never put me in it. THAT’s what I thought was a bug.