Guimbal Cabri G2 no engine power at high altitudes

So we can agree:

  1. in real life the G2 is not to be leaned.
  2. stay in the lower elevations/density altitudes.
  3. the rich mixture and lack of leaning are partly due to the cooling of the engine

What remains is the reason for this bug:
a) is the G2’s engine behavior at 9000’ correctly modeled? Should the engine behave as it is? The graph says I can hover at 9000’ but the sim did not reflect that.

The helicopter was certified for 13000’ What will happen if I take off at say my home airfield’s 5584’, and climb to 9000’ in the cruise (rather boring to climb that high) without leaning?

===> Please before anyone replies, please also try this flight for yourself. <====

            KTEX 9000' ISA+10  1232 lbs take-off weight, no wind.