The UI does not react to any changes made to the database for comments sections (i.e. upvotes/downvotes don’t show up, comments get an infinitely spinning wheel but are posted normally, etc.,) This could lead to doubleposting, but mainly it’s just not how the site is supposed to work.
Problem first encountered on !furry, if that helps
Dankojn pro auxskultontajn, Kamarada Felano
(Edit: Also happens with posts.)
This appears to be a known bug in the current version and will be fixed in the next update. EDIT: Keeping the page open for a few seconds seems to get it to catch up, though in the worst case it can take a minute or so…