Inkarnate

Howdy ya'll, thanks for takin the time to read this.

I'm fairly new to Inkarnate and I'm mostly getting it to do what I want it to, with one exception. I started with a world map and as needed made child maps to get more detailed, however I find that with each child map I make, the grid scale remains based on the original world map resulting in each square on the grid taking up more and more room on each child map as the maps cover a smaller area of the world map. Is there any way to reset the grid scale on a child map so the squares are smaller without starting a whole new map and simply tracing the old one?