When zooming into large inserted png the image disappears.

Windows 11, Coreldraw 2021, Lenovo P1 laptop

I use Greenshot to do screen captures.  I have pasted four screen captures into a Coreldraw document.  Greenshot makes .png and I think the largest of the four screen captures is about 1200 x 1200 pixels.  I have locked all four images and now I want to draw arrowhead lines show the relationship of items depicted in the screen shots.  When I zoom into the image to draw a line the image goes away and leaves just white screen in that area.   This doesn't happen on the slightly smaller inserted screen captures.   

What is causing this behavior?