The new update did something to wheeled vehicles.
So when your wheels get destroyed and you repair them they don’t come back on anymore. They will show up on X-ray and the game will tell you the vehicle has been repaired, but the wheels stay off. This will cause constant jerking or limping when you try to move the vehicle.
More players are also reporting this bug on reddit.
I did a little bit of extra testing.
When you have the bug, and you drive your wheeled vehicle at full speed into something, which would normally break the wheel or wheels … the wheel becomes visible again, but it will not have collision and only basic textures (no dirt. damages, etc).
The game will still claim your vehicle is ‘repaired’ and the wheel will still be there in the X-ray, but the now visible wheel is still practically not there (no collision, will sink through terrain, etc).
Edit: for reference, I did all my testing with the Fox, but multiple wheeled vehicles get reported on Reddit.
You can bug report it here: Gaijin.net // Issues (just search a bit first so that you don’t report something that is already reported and known about)
A guide on how to report bugs can be found here: ([Navigation] Technical Knowledge Base | War Thunder Wiki)