Is my plane meant to slowly decend automatically.

Hello im new to flight sims and flight sticks, I recently bought the Saitek x55 rhino and iv noticed that if i do not touch the stick my plane slowly starts to decend is this meant to happen, would love any help that can be provided, thanks.

If you've got the autopilot on then no it shouldn't descend but if not it will descend or climb if you haven't trimmed the aircraft.

It sounds like you don't have the aircraft in trim.