Good Day,
I think the instant search only give result in if the item is in that page.
I.e. may table is consist of 1000 items and I make the pagination 25 items perpage.
when you search the product sku it only show the item that are on the current page, but if you search a product on the page 3 it will now show in the instant search.
Can you check why is this happening.
Thanks