This is a serious bug. Those cannons can only shoot in a very weird angle and they cannot shoot anything above players. All the bombs will explode at the same location of cannons instead of shooting out. It’s impossible to finish this mission now. I tried about 2 hours with all 6 cannons. I only made those shot for 23/30 (because there is only one cannon at least can shoot frontally and be able to hit some of those bats). I checked all the YouTube videos related to this mission, none of them having this issue before 9.1.5 update. Could Blizzard send someone to fix this bug? This is a mission on the main mission line. If I don’t finish it, I can’t even move forward my missions stage in WOW: Legion DLC.
I saw people posting the same issue said that he was able to finish it because he manually attacked those bats by using starfire (he is a druid). But I play as a warrior character. I have no way to reach those bats by my melee attack now.