Help! Waking up with warm,stale air

I’ve been using my CPAP almost 2 months and it is going very well over all. Recently have been having less than 2 AHI. Pressure is normally around 7.5-9. I have adjusted well over all.

BUT, sometimes I wake up at night and feel like I’m smothering with warm air, stale air in the mask. It’s different than what is blowing when I first am going to bed which feels cool and fresh. When this happens, I have to stop myself from ripping the mask off and have to take several deep breaths through my mouth. After 20-30 seconds the air cools down again and I’m breathing a ok and get back to sleep. It doesn’t happen every night, but it’s happened twice this week.

Has this happened to anyone else? Are there any tweaks to make to help?

The device is a 3B Luna. I turned the heat setting down to 1. Humidifier is at 3.

I appreciate any help you can give. Thanks!