When you select Unconnected Profiles, under the Find menu, and press the green ‘total’, in the top row, in the middle of the page, and search for a specific surname, it no longer returns profiles with that last name.
I used the WikiTree Plus search function recommended in this G2G, https://www.wikitree.com/g2g/1096910/find-unconnected-profiles-search-function-has-changed
just an fyi, it is broken.