I have set a date field (using Builder) but the date picker does not pop up when I click into the field - it only lets me type into the field like a regular text field. Is this a bug, or do I need to do some config?
I've just tested with the date field type built with the MB Builder and I see it works. Can you try deactivating all plugins and check it again? I think there might be a JavaScript conflict somewhere.
Can you also check if there's any error shown in the Console when editing a post?