Minecraft 19w02a, Minecraft 19w03a, Minecraft 19w03c, Minecraft 19w04b
Maps lose all their markers when being locked in a cartography table. Affects banner markers as well as green arrow markers.
The attached pictures show a comparison between a map before and after being locked.
- Create a map
- Right-click a banner with it to create a marking point
- Lock the map in the cartography table
-> It has no markers on it