I'm having a similar problem with my new mask which is the Resmed F20. I'm recently diagnosed with Central and a little bit of Obstructive and recieved a Phillips DreamStation Auto-Pap with a range of 5-15. Once it gets over 10 my face just turns into 'chipmunk cheeks'. When I called respiratory they said it was from the pressure and I have an appointment to change masks, in the meantime I'm stuck with this one and have to do 4 hrs a day of use to satisfy insurance. I'm trying tonight to breathe through my nose and see if it helps. I think someone really messed up on the design of these, I thought maybe the F30 would be better when looking at alternatives.