Good job on posting the image.
Friday the 13th is mostly Obstructive apnea; and it occurs in clusters.
I would wager it's positional. Often OA is worse when on one's back.
It appears that you need more pressure during those times.
If it were me, I'd switch to VPAP Auto mode and keep the same Pressure Support (PS) = 5 cm-water.
I would start the minEPAP at 6 cm-water; and give the machine some headroom by setting maxIPAP to about 15 cm-water.
INFORMATION ON APNEA BOARD FORUMS OR ON APNEABOARD.COM SHOULD NOT BE CONSIDERED AS MEDICAL ADVICE. ALWAYS SEEK THE ADVICE OF A PHYSICIAN BEFORE SEEKING TREATMENT FOR MEDICAL CONDITIONS, INCLUDING SLEEP APNEA. INFORMATION POSTED ON THE APNEA BOARD WEB SITE AND FORUMS ARE PERSONAL OPINION ONLY AND NOT NECESSARILY A STATEMENT OF FACT.
I agree with Mongo with one little exception. I would make your min EPAP 7 instead of 6. I think that Mongo was playing it cautious like one should by not making too many changes at one time. Your events are mostly OAs and an increase of EPAP should help but it is best not to increase too much, too fast. Make a small change and use it for a while before you evaluate it and decide where to go from there.