That sounds like a posture problem to me. AL80s are pretty butt-light, especially when they are near empty. Then you are throwing an extra 10 lbs on the top camband, last time I tried anything like that it was a serious chore to stay in trim (and I never did it again). HP119s can be very butt-heavy if they are 7.25" diameter tanks, my HP120 takes a lot of effort from me to stay in trim, whereas I can trim AL80s, LP95s, LP85s, and HP100s with relative ease using a 4/3 wetsuit and little to no weight (if I am carrying weight, it's normally just a few pounds on the bottom cam-band, since I prefer to dive weightless).
If I were you I would try to find a friend with a video camera to go on an easy dive with me and shoot lots of video, especially stopping and attempting to hover. I would also do a proper weight check at the end of the dive, just to ensure that I'm not overweighted. But that's my opinion.
If you need a guide to proper posture, you can look here:
Deep-Sea Sherpa Horizontal Trim 101 Levers .
Peace,
Greg