When zooming out with a map, maps do not align properly to the grid and thus cannot be linked together in item frames to create large scale world maps. This may be due to maps now being created as player-centric rather than relative to the map grid.

To replicate this issue take two maps generate one at the default zoom, then use paper to craft a zoomed out version of the first map.

Go just past the edge of your now zoomed out first map and generate a second map at the default zoom. Craft a zoomed out version of your second map and observe that it is created with many areas overlapping on the two zoomed out maps.

The image shows the issue. The top two maps show the default zoom and the maps align properly. The bottom two show that when zoomed out maps do not align to the grid properly. The bottom two maps were generated as described above. As you can see there is overlap in the bottom two maps where there should not be.