text content disappears when moving columns

This may sound too simple, but sometimes when I move things around in InD, like a large image or section of text, it disappears, then when I scroll up to the page above and back down, it's there. It seems redraws the contents when re-displaying. 

Also, your text thread may have broken. Press Ctl/Alt/Y (on PC, not sure for a Mac) and click inside the any text frame and you can see whether the thread line into the empty text frame is still there.

Do you have any objects on a Master Pages that have Text Wrap applied?

I think you need to post some screen captures (before and after) to illustrate what you've done. Also give us some system information: Please tell us what operating system (exactly) you're running. Please tell us (exactly) what InDesign version you're using.