Hello.
I was disconnected from MW Warzone mid game due to connection lost, and was not able to go back online within battle.net.
The retries did not help. I performed all the actions recommended here and they did not help as well: Can't Connect to Battle.net Desktop App - Blizzard Support
I was using the same laptop, the same wifi, IP and settings as always, nothing had changed. Never used a VPN or anything like that.