Custom filled maps from 23w31a and earlier do not upgrade properly in later versions

Custom filled maps that worked fine in version 23w31a and below do not work upon importing the map file into worlds in versions 23w32a and above.

Steps to reproduce:

1. Open Minecraft in any version higher than 23w31a
2. Create a new world and copy the attached file (map_4073.dat) into the data folder of your world. Use

   /give @p filled_map[map_id=4073] 1

   to give yourself the Map.

In 23w31a and below you will see a road sign on the Map like you can see within the screenshots. In every version after 23w32a the Map doesn't work anymore and is blank.