buttons wont disappear on pop-ups

I have a simple yes and no slide where users read a question and select yes or no. Depending on what they select this will bring up a pop-up box with additional tips. However i have added buttons to these pop-ups (so they can move on to the next question) to close them which it does do however the buttons remain on the screen and do not seem to disappear with the pop-ups

Any advice would greatly be appreciated