Increasing frustration with DENA

So I like many players have had issues with the game crashing since September but it was only on screen changes, after this last update though I can't even finish off the bosses now because the game just locks up and dies. Yes I know they don't support android 4.0 anymore but I'm using 5.0 so until they announce they aren't supporting that anymore I don't see the problem. I really like the game but at this rate how am I expected to freaking grind a boss for three hours because I have to deal with crash rng, this is getting ridiculous especially if I'm expected to pay 200+ dollars to play a freaking mobile game -_-