whenever creating a new map there is grey block scattered all over the map instead of visible terrain. The biome im creating the map in is a hilly desert.
What i expected to happen was the map to be showing the terrain within the limits of the map

However, when i right click to use the blank map either inside my minecraft house or outside of it there are random grey blocks all over the map.

i couldn't say what the steps would be it seems be a glitch or bug with the maps rendering, but ill include the steps i did right before i made the map
1. get piece of paper out of top large chest ( stacked four high with no block in between
2. take shield off left hand
3. hold map and right click to use map