Do you have Moomba cruise? Our boat has the same issue with the cruise on if you really hammer it. Slow throttle and it is fine. Ours has been this way since it was new.
I just figured that was the way it worked...
2007 Moomba Outback V
2015 F-250 PSD CC
2012 Fuse 40 T-bar
Sky Ski Le-38
XXX front wing
UFO rear wing
Evo tower