If you are using Unreal 5.0.3 you should start by disabling sleep globally as it is buggy and causes several issues with the physics. Use p.chaos.solver.SleepEnabled 0 at the console.
Beside that, you also need to check the collision volume of your vehicle. It has to be equally and uniformly distributed to avoid imbalances. Chances are that if you use the original asset provided with the tutorial it will hover just fine, but with yours there may be a front/back or left/right mass imbalance which causes issues. You can display the location of the Center Of Mass through the advanced display properties of the viewport of useful.