I have trouble keeping my mouth closed when I sleep(especially when I use a nasal mask). So, last night, I bought a chin strap from Amazon(same day shipping). On average, with CPAP, my AHI flirts between 2-3. Some weeks I’m consistently between the 1.5-2 mark. This, however, reduced my numerical index to .06! The number could’ve been even lower if I went to bed at a better time, and didn’t eat too close to bedtime. That being said, I’ll have to do more experimenting. But hopefully this helps someone in the community. Stay strong. Keep persistent. You can beat this!