Hi Realtor... I can sympathize with your desire for warmer humid temp... Especially with the Uber-dry northern home humidity levels that come with heating season (I know all about those 5% humidity levels...).
Finally took a close look at your report... I notice that your pressures (page 2) are actually in the lower part of your range. Looks like you rarely get close to 11, let alone 14.
Having had an S9 and similar experience with a plateau (and eerily enough, almost identical settings), I found that dropping the min and max by 2 (making pressures 6-12) worked wonders - AHI figures didn't really change, but I woke up more rested.
My doctor told me that I had taken to therapy very well and it sounds like you have also. So you may have properly retrained your breathing and MAYBE can use a lower pressure range.
Also, after a period of PAP therapy, many users end up shortening (or even eliminating) the ramp time. For myself, dropping ramp time to 15 minutes from the default 45 seems to signal my body to fall asleep faster.
Key with any testing/experimentation is to try new setting[s] for say, a week, and use the software to monitor changes. And try and be patient... After I dropped my pressures a bit, my first night had an AHI spike [ack, what have I done?] followed by a steady decline back to what it was before i.e. ~2.0 +/- 0.5.
Interestingly, while I dropped the minimum pressure by two, median pressure only dropped by one, signaling that I was approaching my own "sweet spot".
As you've discovered, AHI, while important, isn't the only requirement for a good night's sleep. Take a critical look at your bedroom.
Some possibilities include being an overly bright alarm clock disturbing your sleep, too hot or cold room temp, "dead air" syndrome [fixed by a ceiling fan on bull low just to move the air in your bedroom], a mattress that is no longer suitable [age DOES change both the mattress and what you may actually need in a mattress - my better half is doing better with a softer pillow-top layer, and I seem to be gravitating toward monk-like hardness
Don't forget the pillow. I have a fancy CPAP pillow, which (if I had REALLY read the instructions - DUH) has a memory foam side and a conventional side... memory foam and I don't agree - by simply turning pillow over [cue angelic chorus] my personal bad sleep indicator - restless leg syndrome - has calmed down.
This is all a process... your solution will be what works for you - take the changes one at a time, note any results, good or bad, and if you get discouraged, try to remember how REALLY lousy you felt before PAP therapy...