Next button on Blank slide doesn't work on the first try

Here's a new one for me. Prior to questions, I have a blank slide giving instructions. The user needs to click on next to advance to the first quiz question. I've done it this way for years (although put a picture in the background/layout, which I've never done - doesn't seem related though).

For some reason, now the Next button on the player doesn't work on the first click in any of my quizzes. I thought it always worked the second time, but the tech guy who is testing my meeting said that it's sometimes taking him three or four clicks, and it might depend where on the button he clicks.

Anyone have this issue? I could probably just take the blank slide out, but I'd rather not.