I think they are trying out stuff for which you are an 'alpha' tester (lucky person).
My guesstimate half-answer to your second point is that you are searching from a tree-person page, and with the first search the search engine disregards dates. Apparently they are invisible to the search engine, so the search engine is following code to act like they are not there. Including prompts.
I don't know why they can't get the search engine to recognize entered dates on the first search from a tree, but it is most aggravating to have birth and death dates disregarded from a date-bracketing standpoint.