When you draw a filling with a hatch it gets as default the drawing scale as the hatch scale. This can be changed on 3 levels, the drawing, local or common. 

On the drawing, you double-click on the hatch and change the scale there. 

The local and common settings are changed in standard admin under variables. The variable is beginning by the material you choose e.g. LAC. The variable for LAC will then be LAC_FILLING_SCALE. There you can set the scale under Value. Next, you return to the drawing and refresh the settings, Base -> Refresh settings and properties. Lastly, you redraw the drawing and the adjusted scale is set, Element -> Draw Element. 

In the example below, the scale is changed from 30 to 5 on the common level.