I do not know if this is related to your issue, but I notice that some of your listings have an item location of "United States, United States", rather than an actual state location.
Not listing an actual item location (or other policy violations) might affect whether your items appear in a search.
Using an item location of "United States, United States" can often be an indication of a seller involved in retail arbitrage (waiting for an order to be placed before buying the item from a retail site and shipping directly to the buyer) or some other sort of item location misrepresentation, which is against eBay policy. Perhaps eBay is attempting to crack down on such users, and your listings are getting caught up in such an effort (though it does not appear to me that you are actually involved in any retail arbitrage).
