Any clues to why my oxygen is so low based on sleepyhead?

or just a local doctor if the symptoms warrant it, double checking is a good thing.
I don't think raising min to 9 will change anything there. It still may help your apnea, but that may have taken a backseat for a while.

The way spo2 can be inaccurately measured, is something to take onboard too
https://www.amperordirect.com/pc/c-puls ... tions.html
Carbon Monoxide
Carbon monoxide molecules, even in a small amount, can attach to the patient's hemoglobin replacing oxygen molecules. A pulse oximeter cannot distinguish the differences and the reading will show the total saturation level of oxygen and carbon monoxide. If 15% of hemoglobin has carbon monoxide and 80% has oxygen, the reading would be 95%.

This can be dangerous. A pulse oximeter should not be used on people with smoke inhalation, carbon monoxide poisoning, and heavy cigarette smoking.