Wrong damage in Battlegrounds

I have played by Cookie the Cook against Mutanus the Devourer. I won the battle with 5 level tavern, Brann Bronzebeard, King Bagurgle and 2 Coldlight Seer. 5 + 5 + 5 + 2 * 2 = 19.
The opponent had 18 hp, 19 were summed up, but 14 were inflicted (There was no protection at 15 anymore).

I literally had the same situation a few minutes ago. Me and a friend ( we were on discord ) were the last two remaining players. In one of the last rounds we had a tie, atleast from my view, but on his side he just dealt ~11 dmg to me. Seems to be an unknown bug or so, idk

Same thing happened to me at least twice today. I should have gotten the kill and the game showed dmg and the attack animation but the opponent lived.
Maybe it happens more often, but its only really obvious when it’s the last HP, I don’t check at the start of a game if 30 - 5 is really 25 after every round.

Even though blizz doesn’t mention it in the known issues, that’s a bug the community is well aware of
For some unexplained reason, the game will sometime desync players.
Each player will see a different fight, and only the outcome they see happen to themself will count.
If you see yourself losing, that will happn to you and you will lose hp.
But if you see yourself winning, what will happen to your opponent depends on what they see. So you can see yourself killing them or just damaging them, but they will survive or take a different amount of damage, or even nothing, depending on what they saw in their version of the fight

There’s a lot of bug reports for players not dying when visibly killed, these are the same bug but just with a different outcome

This is the 4th time that bug is in the game, and it’s here since quite a long time now, but this time no one knows what is the trigger for it.
The first time was when they introduced the lich king. His hero power was the trigger.
The second time (I believe) was when they introduced Diablo. I think it was either his secret or the round where every one fights him
The third time was during the showcase event hosted on a private server for the release of anomalies. This one was the most extreme one and never hit live servers, but when players had a game with double deathrattle, the deathrattle where never doubled for the opponent, so each player saw extremely different fights.

I may missremember some details but this is the general idea