First be sure you are looking at the entire list and not just a subset, such as a particular category or just active listings.
https://www.ebay.com/mye/myebay/watchlist?custom_list_id=WATCH_LIST&filter=listing_status:ALL&page=1...
Listings that end should remain on the Watch List for at least ninety days unless eBay removes the listing sooner for a policy violation.
Listings that are automatically relisted should continue to remain on the list.
If a seller ends a listing and manually relists so that the item gets a new item number, the old ended item should remain on the list for ninety days with a link to the relisted item that can be used to add the new item to the list, but that link must be used before the old item expires and is removed.
Sellers can also edit an existing listing to sell a different item; in that case the listing remains on the Watch List, but the new item appears rather than the original item.
Once an item has been removed from a list, the only way to add it back is to find the item again (if possible) and add it back manually.
