I saw this yesterday and wondered why the membrane would keep blowing out. This morning an idea occurred to me. Have you checked to make sure that the sizes agree, i.e., putting a small membrane into a small mask?
My husband and I share the same CPAP experience now and we both have the Quattro FX masks. His is size medium and mine is size small, and I thus wondered if this could be the problem.
I think if you have not found a solution, it's time to go back to your DME and have them take a look, perhaps even giving you a new Quattro FX mask or new membrane or both.
Same issue here but not has bad now
i found that if i use ky jelly ( or any water based product ) on the seal and the frame and a elastic band put over the nose piece and bottom vents its pretty good
i also found that a lot of the time the head strap would slide down my head a bit so i just slid it back up my forehead and into the correct place