Morning headaches again after years of good sleep

Male 72, 170lbs, 6 years good results and suddenly these last 4 months I am waking with the old morning headaches which brought me to cpap in the first place. Not as bad now as before. AHI is about 1.5, no problem there. Equipment S9, pillows mask. Start sleeping on Right but find myself on my back soon. Gained 10lbs since starting cpap plus a belly that wont shift.
Love the machine. Any ideas anyone re the headaches? Can't really say that all is well if headaches prevail. I don't replace the mask and pipes too often as I would rather spend money on golf. Well nobody is perfect.

Do you use a software like Sleepyhead to check the machines data, If so you need to post that. Leaks are possible, to many the data becomes unreliable.

Maybe a overnite O2 Pulse ox data check. Maybe time to see a Dr. also. Jim

Any new furniture in your immediate sleep area ? Night stand, mattress, etc. ? Outgassing of formaldehyde or other compounds can give me a splitting headache every time I'm near them. Just a thought... Good luck.

Have you gained even a little weight recently? It's amazing how much difference it can make.