The following is based on a decompiled version of Minecraft 1.10 using MCP 9.30.
The bug
The tag map_tracking_position is not read from a filled_map if the tag map_scale_direction is provided. This is kind of strange because they don't preclude each other. The value of map_scale_direction is added to the scale and map_tracking_position determines whether or not a marker for the player should be added to the map and updated.
Affected method: net.minecraft.item.ItemMap.onCreated(ItemStack, World, EntityPlayer)
How to reproduce
Use the following command
/give @p filled_map 1 32767Look at the map, its scale should be 3/4 and it should not show your position
Replace "###" with the data value of the map you just gave you
/setblock ~ ~ ~ furnace default replace {Items:[{Slot:2b,id:"filled_map",Count:1b,Damage:###s,tag:{map_scale_direction:1,map_tracking_position:1b}}]}Look at the map
→ You will see that onlymap_scale_directionchanged the map (3/4 scale became 4/4) scale
To prove that the map_tracking_position tag works:
Use the following command
/give @p filled_map 1 32767Look at the map, its scale should be 3/4 and it should not show your position
Replace "###" with the data value of the map you just gave you
/setblock ~ ~ ~ furnace default replace {Items:[{Slot:2b,id:"filled_map",Count:1b,Damage:###s,tag:{map_tracking_position:1b}}]}Look at the map
→ The map tracks now your position
It appears in 20w07a (and probably earlier) the mentioned method
MapItem.onCraftedBy(ItemStack, Level, Player)(Mojang name) does not read whether the map should track the position anymore. It is only stored in the map data astrackingPositionand appears to be read correctly.