Not even five months with new AirSense 10, and it keeps missing a lot of my hours

I posted viewtopic/t190205/New-Airsense-10-somet ... hours.html earlier this year, and the one response - that the clock was wrong - was inapplicable; the clock was correct.

The problem stopped, for three months, but is now back. Six times in the past two weeks, it's credited me with under six hours of usage - four of these times it's been <3 hours - despite the fact that I am masked up for 7.5 hours minimum, and almost never leave bed (that is, mask never comes off until I'm done).

Last night about half an hour into my sleep, I noticed trouble breathing, the knob/dial was lit, and the green light on top was blinking. The display said something about my tubing being blocked. I have no idea what I did, but without reattaching the tubing, I got airflow coming again, the display indicated so, and the knob and light on top turned off. And yet I only got credited for 1:32 of use, although as usual the actual time was closer to 7.5 hours.

What's more, I can't even correlate the short and inaccurate usage times to any reality. On the rare nights I get up to use the bathroom, the number doesn't match my usage before or after the interruption. It's not number of hours before or after midnight I used it.

What can I try? And I didn't get the exact wording of the blocked tubing message, but what could have caused that? I clean and dry the tube interior every week.

Okay, one thing I just thought of: I have used the same tubing for three years, figuring it's in good shape, and I maintain it well. Could this old tubing be a reason for the problems?

From ResMed's troubleshooting:
The following message is displayed on the device: "Tubing blocked, check your tubing"

Note the last option: "Replace main PCB if the above solutions do not work"
Given your machine's long tim misbehavior, it seems the problem is in the PCB (printed circuit board) and not in the tubing.