This already happend to me twice. I was in a Comp match playing as Ana and suddenly I got kicked out of the Game with the Note: Lost Connection to the Server. After that i got a Penalty for 15 min and lost some SR.
Disconnections are no fun, but they can happen for a variety of reasons. So we’ll need more information on your part in order to help you. Remember to stop playing Competitive play as penalties will not be reversed for any reason and try to start with these starting troubleshooting steps.
If you successfully work through these steps and find your connection is still dropping, let us know and we can work to help narrow down where the disconnection may be happening.