BF 109 G6/AS engine setting oscillation above 8000 below combat setting

[FTC_ChilliBalls]

Just tested this after having heard it from a mate, 

the BF 109 G6/AS' engine, when above 8000m and engine settings below 2400 RPM,

will have massively oscillating RPM, ATA and prop pitch. 

It's impossible to go below combat power setting without causing this behaviour.