Not all the theme files at this site have been updated to Tiki 5, and Tiki 5 itself is still in flux, so as the page-top note says, there could be some weirdness happening.
The Judy theme in particular needs updating. The site header items were overlapping the theme-switching module, which made escape from the theme problematic, so I moved that module down a position and moved Registration info up one. Now it should be possible to switch themes using the module even in the Judy theme.
-- Gary