An issue with autopilot

[FKW]

When leveling on autopilot sometimes the aircraft keeps the nose up instead of level flight. Ok it keep either speed and height but I want to know if posible to correct it.

[Nav]

Aeroplanes (real or simulated) often trim out to a nose-high attitude if they are A. carrying a heavy fuel-load or B. flying very high or C. both!

Probably you're experiencing that at the start of a trip, with full fuel.  If so it's normal/realistic, and will sort itself out as the fuel is consumed.  The other way to avoid it, on short trips, is to carry less than a full load of fuel.

[Nexus]

it's completely normal to have the nose pitch up a few degrees in cruise.

The air density is much thinner at say 30.000ft so the angle of attack needs to be increased to get that extra lift in order to maintain the desired altitude.
Try to slow down and the nose will further more pitch up because speed and Angle of attack is related. Faster you go, less AoA is required to maintain altitude.

[FKW]

Thanks for the tips. LOL I was flying on short distances with full fuel