I am having a hard time trying to hatch fill cursive for laser engraving. I made the font a object to path and ungrouped them to move letters together. I then selected them all and union them together and combined. It looks great and I have laser cut the word out and that works great but when I try to fill in the word with hatch lines it disappears. I don’t know what I am doing wrong can anybody help me understand where I am going wrong or how to fix? I saved it as a .dxf file. 

Looks like the same issue as:

https://inkscape.org/forums/cutplot/exporting-to-dxf-with-filled-shapes/