Pardon my ignorance, but does the Arruis have a bleed valve on the compressor or a similar device?
I know that on several occasions with a Bell 206 Jetranger that I flew, a sticky bleed valve caused a high TOT at a low torque setting with a related low N1 reading.
The company I worked for had so many strange incidents with the EC 120's, eg blade strike after a downwind landing and the door flew completely open as there was no door strut attached.
Yep, in the full open position the door extends above the blades when rotating making for a spectacular noise and lots of u/s spares. The list goes on, but this is a complete new topic all on its own!
Good luck!