If the CPAP is the automatic type that adjusts its pressure, breathe exclusively through the mouth eight times, then through the machine (use “nose pillows”, not an over-the-face mask). This tricks the machine into increasing the pressure - which can help with sleep.
A different trick that does not work as reliably is to resist the pressure just a little bit as you breathe in, then breath out a bit more quickly. You may get a little breathless this way, so sometimes it feels like it is more trouble than it is worth. The goal is to trick the machine into increasing the pressure a little bit.
(YMMV: Your mileage may vary.)
Thanks- my dad has nose issue where he can’t breathe hrough nose- so he has to use face mask- he was given nasal ones to try, but can’t use em-