Dry Mouth without humidifier

[condition]

Hello, after strangling with settings and masks, I have stabilized, at around 1.5 to 3 AHI.
The last three days I have not used the humidifier. (Have not attached the humidifier but is listed as level 1)
I have set the tube temp to 26C or 78.8F.
I also slightly untight the mask F40, to avoid under nose bridge morning mark. 
I am a major mouth breather, so much so that if I use pillows and mouth tape, I wake from the air trying to escape the tape.
I spent a small part of my sleep lying on my back, my AHI from the sleep study is 33, but all night I slept on my sides, on a home test.

The tip of my nose, very easily irritated for years (without cpap), feels so much better with the mask looser and with the humidification disabled.
However, I wake from very dry mouth all these three days.
So, my question is the dry mouth from the dry air or from leaking? Can I have even less humidification than the 1st setting?

I attached the last three nights screenshots.

[condition]

    I attach here the sleep study, I am male at 53 and using cpap since past April. 

I find that humidification of Airsene 10 depends on the mask, regardless of the setting. 
I use hybrid full face masks only, to avoid morning marks and recently acquired the evora FFM. I noticed it does not have nostrils' separator and seems more aggressive in ventilation and humidification. For example, I load the humidifier till the first line, and with the F30 & F40 masks, only 10% of the WFI is used and I throw the remaining. Now with the Evora FFM, the whole load is humidified, giving me irritation to the nasal tip and the tissue separating the nostrils. I would test this mask more, but I can endure only a low-level humidification.