Uh oh. I use emoji in several of my personal post tags and as of today such tags do not work when clicked from a post's tag list. (platform: Win 10 Firefox)
Clicking a chost's tag of "#wave 📷" for example now degrades into "https://cohost.org/rc/tagged/wave%2520%25F0%259F%2593%25B7", a "tag" for which there are no associated chosts.
However manually pasting "https://cohost.org/rc/tagged/wave 📷" into browser URL field still works. As does any hardlink made to the emoji-bearing tag (for example). (Note: I had to manually type %20 in place of the space character in that tag for that hardlink to still work. I think that is another case of the regression.)
Similarly "#wave 🎵" degrades into the non-working "https://cohost.org/wave/tagged/wave%20%F0%9F%8E%B5".
I'm sure there is some technical reason why this is happening now but it does break tags that contain emoji and personally, I think it's a fun feature to have and support. I hope Cohost's tagging engine will walk this back and continue to robustly support emoji in (or as) tags.
edit: @snippid has a bug report created.
P.S. Found a definite second bug too just now re: image uploads:
The original filename for the screenshot I attached to this post was
Clip 007199 FF[2982] cohost! - #wave%20%F0%9F%93%B7 — Mozilla Firefox.png
This resulted in the image not displaying (the browser showed a "broken image" icon instead). I assume the hashtag or percent characters confused the site. Renaming my file to
Copy of Clip 007199 FF[2982] cohost!.png
and redoing the upload has the image displaying properly.