InDesign disappears when I click outside of application

I am a Mac user that uses InDesign to make brochures, booklets, etc. I copy and paste copy a lot from different applications and when I click anywhere outside of InDesign, it moves to the bottom of my desktop so any applications opened in the same window go above it while InDesign goes to the bottom. This started happening earlier this year but I couldn't find anything online to try and fix it. I reset preferences and reinstalled the application and it still does this. Any help is greatly appreciated!