I own an RTX 3080 and have had RTX work in the past. Upon trying several of the worlds downloadable on Marketplace, I'm unable to load the RTX portion of the worlds the marketplace lets me create. Some other worlds, it won't let me download because my system "does not meet minimum requirements, such as an RTX 2060..." and so on. I updated my graphics drivers, reinstalled minecraft, restarted my computer, and updated my graphics preferences in the displays tab on windows settings. Nothing has proved to make minecraft recognize that my system does, indeed, meet minimum requirements.

Specs------------------------------

Windows 10 Enterprise (10.0.18363)

AMD Ryzen 7 3800XT

ROG STRIX B550-F

32GB of Corsair RAM

RTX 3080