I'm currently on Visualize 2019 SP5
It is similar to this issue that Dale posted: https://forum.solidworks.com/message/959568?q=duplicate%20decals%20disappear%20applied%20in%20Visualize
I am having the same issue that Dale posted, so I started importing and applying decals directly in Visualize (and not importing them from SW thru Live update).
Now, I have multiple models in my Visualize project that I apply the same decal to. I'm finding if I apply the decal to one object, it disappears from the other object. Is this a limitation in that you can not apply the same decal to more than one face?