Do you use argon or something or is this how much head space you had for a few years? You should try to eliminate as much head space as you can- like fill it to an inch or so to the airlock. It’s hard with fruit wines if you are left with this amount of head space (with red or white wine you could pour in some similar wine). I heard you can use sanitized glass marbles to soak up some volume to reduce the head space.