InDesign version 17.3
A Metadata Caption set in Text Variables can be on a layer separate from an image. In my workflow, this is good!

Unfortunately, InDesign treats images on layers that are turned off as if they are on, and hence a text box containing a Metadata Caption is presented with multiple images to read from and delivers the message <Multiple intersecting links>.

I discovered this by having a square image on one layer and a 4:3 image on another layer, a layer turned off. When the text box containing the caption touched the top or bottom of the image, it worked, but when moved to the center of the image or the sides, the caption text disappeared, replaced by the message <Multiple intersecting links>. It did not matter if the text box containing the caption was on the same layer as the image or on a separate layer.