I dont know how to describe this bug…
but i have a video of it 
the clip is from the ptr but I have the same problem on live servers 
I posted this 10 day ago on the german techsuppurt but got no response, I hope someone can help me here… I lost too much sr on this
Your connection is unstable, which is why the game is loading/kicking you back/loading etc. The connection trouble icon is flashing in the top left corner to tell you this. Your ping is hitting over 250ms, so it will likely keep happening until you’re on a more stable/faster connection.
This icon pulses when your client hasn’t heard from the server for a period longer than your interpolation delay. If this icon is consistently pulsing, it may indicate a connection problem, and can cause erratic behavior in game.
source: Diagnosing Overwatch Network Problems - Blizzard Support
Two possible causes :