Drive it more than "into the driveway" (like around the block) to settle the ride height and see if the problem persists.

If it does, you will need an physical inspection, and not a bunch of guesses from afar, to get to the bottom of this.

There really isn't any part of a proper 1500 mile transport that should have caused this.

PERSONALLY, I don't quite follow the drove it into a semi description, nor the "secured at the rear only" deal. It sounds rather atypical.