I thought I’d allocate categories to my old topics (which I’ve mostly done). However I think doing this threw up something which might be a “feature” of the system.
After changing the category (by editing), to get back to the list of my topics, I used the “back” arrow on the browser (Firefox under Linux Mint). This worked fine for a few, then the next I tried to change had lost the “category” dropdown contents - it had only the “choose a category” one. The top of page links to other pages had also disappeared.
I closed the SOTA reflector tab, then re-opened it and all was well.
Otherwise no issues so far …