Sure!
https://postimg.cc/r0qLFHsd
I decided to do one more test: I deleted the component override for SP LMS:
shaper_varsita/html/com_splms
After that, the shopping cart reflected both added and deleted items correctly. The shopping cart total amount, though, doesn't show decimals. And, of course, the template styling for the LMS pages changed.
But, at least, now we know the problem is the overrides (I'm guessing the same thing is happening with the yoga template).
Please, let me know how to fix it.