When Assistant threads re-rank by time after their use, they only re-rank after the page is refreshed. They should instead live re-rank, without the need for a refresh.
Unsure if this happens on mobile — I only tested on desktop.
Relates to #8434, where the example video shown evidences that a refresh is needed when re-titled threads are re-ranked by time. Although #8434 advocates for the end of that behaviour!