For threads sorting is broken. Clicking - top, controversial, new, old - does nothing. I'm on a desktop.

What do you mean by "for threads"? The front page (list of posts)? or a post's page (list of comments)? or a specific linked comment thread?

What browser? Have you tried clearing cache/site data?

for me this seems to be working on desktop, both in sorting of posts and sorting of comments within a post