Just Flight Piper Warrior - sluggish controls

I'm pretty happy with JF warrior. I flew the real Warrior only once so far but JF Warrior seems pretty close to the real thing and I actually use it for practicing my real flights. 

Recently I got a weird problem. Sometimes I started a flight with Warrior and found the control was really sluggish. It's like the plane reacts to my controls with a half-second delay and is also a bit too wobbly. I looked at the control surfaces and they acted instantly with my yoke movement, so it's not a hardware problem as far as I can tell. This doesn't happen/change in the middle of a flight. The flight either starts with a "normal" warrior or a "sluggish" warrior. 

Anyone bumped into such problem too? The most frustrating part is that JF Warrior often flies just fine and I just couldn't figure out why sometimes it's "broken". 

I fly with VR exclusively now and maybe it has something to do with system being overloaded in certain cases? But I'm limited by GPU but no CPU in VR.