Not being logged in to Google and not keeping cookies between browser sessions, most of the time Google gives me the standard cookie permissions popup (where yo

Not being logged in to Google and not keeping cookies between browser sessions, most of the time Google gives me the standard cookie permissions popup (where you can enable or disable search personalisation and targeted advertisting), but occasionally I seemingly at random I get the "we can't determine whether you're over 18 yet?" variant instead. I wonder what's causing it to flipflop between the two states…?