A week or two ago (maybe earlier) I started having problems where I’d try to select something from the category dropdown, but the tag list would keep stealing focus. In the following video, I click the category dropdown on https://try.discourse.org/ and nothing else – focus is immediately shifted to the tag list.
It would only happen the first time I clicked the category dropdown. I would have to close/re-open the composer to trigger the issue again. However, on another Discourse forum, it was much more severe, and was almost impossible to select a category:
After switching tabs and coming back a few minutes later, the severity had dropped and was similar to the Discourse demo site. I verified this on the latest versions of Chrome/Firefox on Windows 10 Desktop.