Missing effects - looking for possible reasons? Exhaust flame and vanishing contrails

[Mysticpuma]

Without the usual "because it's broke" shenanigans I'm wondering if anyone has an idea why I am not seeing effects that others have?

I have not yet seen any exhaust stack 'Blue' flames when taking off or at altitude (in sunrise or sunset).

Also my latest test at altitude (using FMB) showed contrails streaming across the sky. When I played back the track, all contrails had vanished even though I was at 7000-7500m.

Is there a setting (with the exhausts primarily) that get the stacks showing flame (like CEM settings?) and secondly has anyone else had the disappearing contrails?

Cheers, MP