Facebook scrambles the date on a post. We were falling back to the current time when we could not read it, which floated old posts to the top of every recent view.
Facebook splits a post's timestamp into one character per element and mixes in decoys that are painted and then pushed out of view. Our reader was picking up the decoys and returning nonsense, and when nothing parsed, both the extension and the server substituted the current time.
That is the worst possible fallback. A three-month-old post looked minutes old and outranked everything genuinely new.
Now the date travels as unknown and stays unknown. Cards say "saved on <date>" or "date unknown" rather than showing an unlabelled number you would reasonably read as the publish date. We also stopped a re-read that fails from erasing a date we had already stored correctly.
The same release made page posts save instantly instead of waiting on a queue, and fixed video and reel detection, which could not use the video source because Facebook does not put one there until playback starts.