My environment is MX Linux, Firefox, and Alby, and I always apply updates as soon as they are available.  My initial issue was that I was not able to select a theme, and it would show me a dialog box to switch to a different npub.  My spouse was able to select a theme (using the same environment, but on different hardware), but she was not able to complete the process once a theme was selected.

Currently, when I select a theme to preview, I get a red banner for a few seconds.  One said something about "profile not found".  Now they all say, "Error: Error: no site".  The page has a drop-down menu to select themes, and a bottom banner with a drop-down menu that says "All Notes", a "Use Theme" button, and my profile pic, but the rest of the page is completely white, no matter which theme I select.  When I click the "Use Theme" button, it flashes, but nothing happens.