As you may have noted, B36, in my original post initiating this thread I acknowledged that tighter is not necessarily better, and can cause issues. However, when "floating" does not do the trick, there is little else to do unless you try a different mask, as far as I can see. I suspect the same mask may indeed float on one face and "fart" on another at an identical pressure. I have read Jeffy1958's post, but I thank you for pointing it out. As I said earlier in this thread, last night I tightened things, and pressures were indeed lower. We will see what happens tonight.
Breathing keeps you alive. And PAP helps keep you breathing!
With my Activa LT nasal mask looser is better usually able to put two fingers between the straps and cheeks otherwise if tight and mashed on my face it would leak like a sieve.
It,s designed to seal when the cushion inflated with pressured air so it float on face, before clip the lower straps turn the S9 on and let the air fill the cushion and use the forehead dial for any adjustment.
When leak goes up it,s time to replace the cushion.