This is persistent on my end too, well more precisely is that the top level page in the menu is not accessible (you can’t click to go to the page), it only open the sub-pages, when it has sub-level pages in the menu. It just opens the menu with the sub-level pages rather than the actual link to the page.
Tested on Safari, Firefox, and GC.
https://www.bretonicsco.com/tests/