I'll check my carpet python book, but I believe I went through a chapter that stated one of the Ssp soaked and had a habit of eliminating it's waste in the water bowl.

Have you noticed any waste within a few days of the soaks?

My coastal has not been spotted fully soaking however one night she had her tail end in the bowl and the next day it was a toilet.

As a whole I don't think soaking is a typical behavior.

Check out temps and humidity in case something was accidentally adjusted.

If you suspect those damn mites, jump on the procedures to find and eliminate them.