Several users in my Xbox Community group on facebook have reported this issue with overwatch and I’m experiencing it too
First of all, make sure that you are connected to the internet.
If you are, and you have been randomly disconnected from Overwatch, with this message showing up when you try to log back in, then you just need to close Overwatch, quit Overwatch (pressing the button with the 3 lines, forgot what that was called, then pressing the second bottom button), and reopen Overwatch. That should work for you since it does for me. Let me know if you are still having problems.
it’s still happening aaa