Problems when starts lessons

Hello everyone. I’m here looking for help with a problem that’s been bothering me since I installed Navigraph Academy. When I start the lesson, upon launching on the track, everything starts vibrating and bouncing. I also get a message about landing gear and tire problems. I can’t stop it. If I start missions while still in the air, it automatically falls down. Could someone find a solution? Thanks.

Hello,

When you say “If I start missions while still in the air, it automatically falls down” Does the aircraft just begin descending? Is there power applied?

The engine is on.

But the plane go down ever