[Motor31]

Air bubbles don't just form up with the rig sitting there. I am assuming the rig was parked and you found the nose lower when you returned. If that is the case you have almost certainly developed a leaking internal seal in one of the front rams. The front legs dropping in transit is another symptom of the same thing. The solution is to replace the leaking ram(s). Lippert uses cheap chinese manufactured rams and they are not rebuild able.

This is not a terribly difficult operation and can even be done by the owner. It will require raising the front to full extension and holding it there while you also dig a hole below the leg. The front ram is long and you will need to remove it from the bottom. Bleeding the system afterwards can be tedious but not all that bad if you have ever bled brakes.