First, we need to understand what "lossless" means in Sheldon’s world. It is a term usually reserved for data compression or thermodynamics.
Here is the current state of the hunt:
While streaming services like Max or Amazon use compression, a "WEB-DL" is a direct capture of that stream. It isn't strictly "lossless," but it is the highest quality available for digital-only releases. Technical Specs to Look For young sheldon s02e10 lossless