RTX beta update not installing; stuck on 1.14.60

The RTX Beta (v1.15.0.8) version is not installing, no matter what. I have tried and re-tried all the proposed solutions.

I have fulfilled all requirements:

• joined with the Xbox Insider Hub ab to the RTX Beta
  I even tried to leave and re-enter the the Xbox Insiders program (deleting my account).
• have an RTX 2080 Ti with the latest (v445.87) driver

I also know that I'm not the only one with this issue: https://www.reddit.com/r/xboxinsiders/comments/g5i6kj/minecraft_beta_wont_install_no_matter_what/