Game & iPhone froze during ad

Between levels of the (Candy) game I’m playing an ad came up. But when I didn’t play the sample game - I did when I first saw it earlier - and was paying attention to something IRL, it had frozen telling me to slide to drop the fruit(?) but nothing would slide, drop, or otherwise move. I tried tapping the double arrows in the top corner where the X usually appears to close the ad and return to the actual game I was playing, and even something in the other corner that might be just a game trademark. But no action of mine did anything.

Has this happened to you? Do you know: How can I unfreeze this ad / screen / game? I was doing well, having a good run, and I’d like to get back to it.