Answer
This is tied to Search Domain synchronization background jobs — every time a background job related to Search Domain synchronization runs, it can invalidate these AQ$ objects again as a side effect, due to a known framework behavior/bug in some releases. This has been fixed in a later update in at least one major release track, with a specific single patch also available for environments that can't immediately take the full update — if you're hitting this repeatedly, it's worth checking whether a fix is already available for your specific release level rather than assuming it's something in your own environment causing it.