I had that problem when using the face mask, but when I switched to the nasal pillows it made a huge difference.
Yup,,, I tried the nasal pillows in various forms, the last of which was the face mask with built in pillows. That worked the best of any, but still had two problems. 1- my chin would drop during the night and allow the mask to leak, 2- they could not crank the pressure up high enough to work when I was sound asleep.
We tried various chin straps and head gear, I even toyed with the idea of buying a football helmet with two way chin straps,,, but at that point the pressure limits made that a waste of time and money.
Then the doctor suggested an oral appliance that moves your jaw forward at night, but I really don't trust that not to cause some other problem with my jaw bone or teeth.
Now what I do,,, is sleep with a neck pillow, (velcro attach type), either sideways or backward. That keeps my mouth closed enough to breath with little loud snoring. I do feel much more rested now, so the machine stays in the carry case!!!!
Did you ever get a wrong phone number at 2am while you're wearing the mask,,, it freaks out the people at the other end!!!!!!
I was screaming in the phone trying to make myself heard, and the guy at the other end, in broken english, "What is wrong Papa, what is wrong,,,, are you dying?". Finally got the mask off and informed him he had the wrong number,,, but what a fiasco!!!!