If these issues are already reported (I guess so but I don't find them here...), don't hesitate to delete my post.
Hardware : Skalarki
Soft : P3D (3.3) and last Jeehell

1st issue :
if you start from "dark and cold", you can start APU with FOB =0.
The APU will be running (KO).
The engine will not start (OK).

2nd issue :
Same situation as above (FOB=0, APU started and engine start process engaged)
As soon as you add Fuel in P3D option, the engines appear to be running (don't need to reinit the start process...)

Hope my explanation are clear (and will help).
And THANKS for your great amazing soft JH!