I just used my grade booster ive got from this week mission for my monster, and it went from grade B to A. When i went back to the real world, the monster was not grade A but B. Is this a bug? Can someone else confirm this? Grade boosters are already so rare, and now it does not even seem to have any impact on my monster 
Save state problem. After using a gradebooster you should click around the app a bit so the game knows to save another save file. Iâm afraid that your gradebooster is almost certainly lost.
Naaa he can go back on the floor he got it from floor 17 and then do it again .
Since the game saves every time you go to town. Every time I get something I was hunting I go to town, leave move a tile, and go back to town just to make sure it did save. I also leave and renter the town if I make any changes and I donât plan to play more afterwards.
When I got my grade booster, I couldnât select any arkadions to improve. It just wouldnât do anything when I clicked the âchooseâ button. I just started clicking, and ended up selecting an already âSâ rated guy and it finally worked. So I didnât get any benefit from that grade boost. Has this happened before?
Just realized what happened. I had gotten a level boost, not grade boost, so it wouldnât apply to level 99 guys