This will never get fixed. Never. Win once in coop, then use bonus heroes in normal 5 on 5 pvp to get the rewards.
The game is completely full of holes, even without third-party software.
2v2 PvP has been buggy since release, and so have cooperative raids…
In my memory, of all the countless bugs that have been fixed in the game, the only ones that have been fixed are the endless solo raid farming and the endless alliance box farming, and these were fixed by the first developers… And even so, there are still ways to boost in solo raids and the alliance box.
PvP, solo raids, cooperative raids, bounties, war, campaign, shops, and even donation purchases - there are bugs everywhere…
Has been since forever. As long as people spend money they don’t care