Pro make me crazy. I done a project with many duplicated maps to patch limitation of Pro in tiled labels.
Now, after doing my layouts, I saw missing link in my TOC. So an other problem I was thinking.
When looking via Catalog view / Dataview, first I saw no missing link in all of my maps. After thinking deeper, I saw that the layers with missing link are show ok. So why making the missing link mark in the TOC
The problem I saw is that I can't be sure if it's ok since, at least with two major layer, they are draw like you can see in this picture. The polygon for my depths are draw and the line for delimiting them also.