First off…there are HUGE problems right now with Battlegrounds animations. They take WAY too long. Having said that, the “solution” is to disconnect from Hearthstone and reconnect. This is NOT always optional. I waited through a battle against pirates recently and when the battle ended, it immediately went into combat with NO time for the tavern. Not even 1 second…
Recently, however, it has started dropping me when I quit Hearthstone, so when I come back into the game, it does not reconnect. My partner (who I queue with) is on an iPad, and he is able to get in and back, but I, on a PC, am disconnected. So this is not a case of simply losing the battle or anything like that because I can spectate my partner and it shows me disconnected.
This is a huge issue. I literally feel like I cannot keep playing battlegrounds because either I cannot purchase or I get disconnected…
For the record, it takes less than a minute to quit and restart Hearthstone. This has not been an issue in the past.