Need Help Understanding and Addrssing FlowRate Anomalies

[Melman]

Attached are several charts for the same night. The first shows the flow chart for the entire night. This is not an atypical flow rate pattern for me. (Yes, I know I stayed up too late, but I see similar flow rate graphs when I’m in bed by midnight.) Flow rate is fairly consistent until about 5:30 and then changes significantly until my bathroom break at 7:30. I’m wondering what would cause such a change and is it any reason for concern?

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Another is a 2 min screen shot from about 1 hr after donning the mask.  Perhaps a trace of flow limitation but I don’t think there’s need for concern.

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The 3rd is a 2min shot from 7:06. The pattern was similar for the entire 2hr period from 5:30 to 7:30. Obvious significant flow limitation and some snoring if I’m interpreting correctly. The pattern doesn't exactly match the examples of flow limitation I've seen.

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Finally 2 min from the hour after my bathroom break. Couldn’t ask for a better pattern.

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So for 2 out of 7 hours I had significant flow limitations (I think).

I looked back at a couple of months of charts and I have similar 1-2 hr periods of similar significant changes in the flow rate pattern and flow flow limitation once or twice nightly for about 30 out of 60 nights. My AHI is always less than one and I rarely have RERAS. I don’t, however, feel as rested as I should. I suspect the issue is positional. I wear a soft cervical collar so I don’t think its chin tucking. I usually sleep on my side but know that I sometimes shift to my back and that may be the cause.  

I’m thinking a minimum pressure increase may eliminate the problem. I tolerate 9cm with no problem and my pressure frequently increases to 12-13cm some nights.  I don’t think a minimum pressure increase would be a comfort problem. Thoughts and recommendations will be appreciated, especially if my thinking is all wrong.

Thanks

[sheepless]

I'm inclined to suspect a positional issue as well. IDK if this applies to you but after many awakenings each night I usually have my longest and deepest sleep between about 4 and 7am. I assume deepest sleep is why I seem to get more leaks and events during those hours. I make it a point to side sleep but lately I've noticed waking in the morning on my back, lip leaking and falling into old habits like thrashing and holding my breath. the trick now is to settle on a method to keep me off my back. maybe like you my best (most refreshing) sleep of the night tends to be after rising for a while in the morning, even after - maybe especially after - a cup of coffee. no joke, it's weird. same thing when I used to take Rx stimulants to get through the day.