A couple issues here:
I had written "see towards the end of this thread", and then double-clicked "this" and clicked the Insert Link button. When the link was inserted, it moved the word "this" to a new line :-\
Second problem: The posting process hung at the step shown in this screenshot, but when I checked the thread in another tab, the post had actually been made. Edit: This post also fell victim to the "Hung on 'Queued for processing'" bug.
Third issue:
When I went to use "text-dragging", where you hold down the mouse button on selected text and then drag it to move it, the post window converts to a "Drop image" mode and I cannot re-position the text. You can see the word "this" in the middle of being dragged through space here.
This is on Firefox on a Mac.