Why am I getting brief messages that an open app isn't responding?

[AC Question]

My Galaxy S7 just started having this issue where, when in an application, the error message "unfortunately 'x' app is not responding" will pop up but then it will immediately go away. It happens in the blink of an eye and it's occurred on apps such as Facebook, YouTube, and chrome.

 

[mhinc]

My Galaxy S7 just started having this issue where, when in an application, the error message "unfortunately 'x' app is not responding" will pop up but then it will immediately go away. It happens in the blink of an eye and it's occurred on apps such as Facebook, YouTube, and chrome.

When you say "x" is it referring to the actual app you are in? For example if you are using Facebook does it say ""unfortunately facebook app is not responding" and so on?
If the above is the case does the app shut down?
Have you tried clearing your system cache?