Android, Firefox. When posting comments it bugs out.

Bad title, but not sure how to describe it in short.

When replying to a comment the new comment feature has a different overlay than previously and if I leave the browser app or open a new tab to research my reply, the comment is somehow no longer attached to the comment I wanted to reply to. By that I mean when I press send it just gets posted as an individual comment to the OP instead of the comment chain. It has happened 5ish times the last day. Thus I am forced to delete my comment and copy it into a reply to the person I wanted to reply to.