This may be nothing, but for completeness I’ll mention it.
You seem to be hitting near max boost rather early, with pressure of 120kPa at 2200 rpm.
On my test with Autoprop, I was between 90/100KPa at 2200 and didn’t hit 120kPa until 2500rpm.
Your test was with fixed prop, and I would expect my pressure would be even lower with a fixed prop.
That’s a significant difference in my book, particularly with a software controlled engine.
For your reference, my no-load (neutral) turbo pressure numbers right now are as follows.
3200 50 (WOT)
Can’t have too much data!