Based on your photo's, the axle has seen better days, years ago.
When the axle is good, you will see 2 inches or so, of the tire, above the wheel.
In your case, it looks like about 2 inches of the top of the wheel cannot be seen.
Further, check the position of the torsion arm. When the trailer is loaded for travel, a horizontal position, as the arm goes rearward, is maximum.
It appears from your photo's that the torsion arm, as it goes rearward, is considerably rising.
That means when the trailer is in motion, it will bottom out. When the trailer bottoms out, many damages will occur, starting usually with tearing up furniture, shearing rivets, severe frame damage, fatigue cracks in the shell, ruining the entrance door hinge, etc.
A good axle's torsion arm, as it goes rearward, with the trailer loaded, will have a downward angle of about 10 to 15 degrees.
The only fix, is replacement. A replacement axle, can have it's starting angle increased, that will give the trailer even greater ground clearance than when new.
The following article, will explain in more detail.