upsidedown

Hi everyone,
I recently purchased an Aquatica A7D for my Canon 7D. I use a L series Canon 16-35 mm lens.On all my test dives with the housing I've encountered huge issues with the live view button, below the surface it just doesn't wanna work. Strange thing is that once I reach the surface the button 'magically' starts working again (kind of)
Any one else encountered this issue?
Another problem I'm dealing with is related to the lever that switches between still and video mode. The plastic piece on the inside constantely comes off despite my efforts of tightening the alan screw that keeps it in place.
Any advice is very welcome. The camera is mainly used for underwater video but I cannot get the button to work and this is a huge set back to my work!
Giovanni