I recently switched from a leaky mask to the N20 nasal cushion and am happy with its ability to seal. But then I noticed that the air would go in my nose and come out the mouth (not breathing in, just exhale). So now I have also added 2 inch "air permeable" cover tape to cover my mouth with overlap over my mustache. It seems to seal real well. I'm thinking maybe I'll end up having to try a Full Face Mask -- have not tried one yet. But since covering my mouth the last few days, there is an improvement in my sleep. And yet on the Oscar report, it shows a leak rate. I'm wondering what it is.
Also, I've noticed a slight headache on a couple of days -- could that be from not high enough of pressure?