2016 Volvo d13 asking regen after regen.

Code I got:
Txld: 0 SPN: 4364 - Aftertreatment 1 SCR
Conversion Efficiency FMI: 31 (null) Count: 1

2 days ago got dashboard signal for parked regen. Did the regen (1 hr). Soot level dropped and I went my merry way.
Yesterday it asked for it again. Did the parked regen (spent 1 hr) but this time soot didn’t drop. So I did the second regen right after (back-to-back another 1 hr). Same picture. Soot level high.
Did the third one this morning. Didn’t help.
Took the 7th injector out and it looks pretty new, no build up. Took the def doser out. It shoots out from all 3 holes.

What should I check more, please help i’m in the middle of nowhere.

 

Did not lose power. Coolant level is stable for 2 days that I was on the road.

 

NOx sensor was changed literally right before this trip (or so my mechanic says). How should I troubleshoot nox sensor?
No visible/leaking exhaust.

 

Milage is 560K. I bought it at 525K. Don’t know when was the filter changed.
I’ll be changing it and the doser.

 

As soon as I get home probably will check dpf status again.

I went to mechanic before this trip to for if dpf filters need replacement. He said they are fine (I don’t know how he checked, probably just hooked up to computer). He said he “… changed NOx sensor and regened the truck which dropped the soot level to 25% or less”.
But… truck is asking parked regens more frequently (everyday). I drive only highway and keep the rpm at 1300-1500 and don’t idle often.
Do you know how those pressure sensors are called? A friend of mine coming my direction so he grabs parts.
Thank You!