Your Surveyor is equipped with a Independent Torsion Suspension System
Caution should be taken when jacking the trailer. A jack should be placed as far outward under the axle-to-frame
mount as possible. Placing a jack anywhere else could mis-align the Camber of the axle and lead to premature tire tread wear.
What I'm saying is, try to place the jack in the area where the axle is bolted to the frame.
This is where I placed a jack, on a previous TT I had, with Torsion axles.
The photo below is of a Forest River trailer with Torsion axles. Should be very similar to yours.