Copied Map Goes Blank When Another Map is Used

What I expected to happen was...:
The map I copied would work the same as the map I had before. Once I switched back to it from a different map.

What actually happened was...:
The new map I created and the one I created it from went blank when I switched to another map as it was updating. Until I logged back in, the map showed nothing but white and a cursor.

Steps to Reproduce:
1. Make a map (it was size 2 if I recall)
2. Copy map by putting it on a crafting bench with an empty map.
3. Shift click map (not sure if it was important that I did.)
4. Switch to another map when copied map is updating
5. Switch back to other map
6. Rage