I had hoped SU6 would have fixed it since it fixed the ATC altitude issue, but when I use AI Pilot in all the default aircraft, the plane never climbs to the desired altitude - thus ATC keeps yelling about being below assigned altitude, and oftentimes fails to assign a higher altitude on the climbout.
You probably already have this one figured out, but if you forget to switch from pressure to standard altitude above FL180 you will be above or below your assigned altitude and ATC will continue to advise.
The altimeter isn’t the problem I don’t think. I set the correct altimeter with B before takeoff and I’m supposed to hold 8000, but my Cessna 172 keeps climbing up to 10K+. Perhaps the Navigraph Navdata did something, but I removed it so it should be back to normal now. A friend who also uses the AI on some parts of the flight doesn’t have this problem and I’d hate to do a sim reinstall just for this.