Is it possible to have multiple motion caption and multiple picture in picture on the same track?

Because it seems that when I try and add them, they erase, modify, and alter each other in the most insidious ways where I simply can't get any work done. One thing alters another, alters another in ways that I can't explain or understand.

Here is a screenshot of a Picture In Picture where there is no image after messing around with it for some time. What happened to my picture? If I can figure this out, perhaps this would provide some insight as to what the issue is.

Thanks.