Single Stroke font ( like font for CNC / engraving )

This may be a font cache problem. Read this please:

Only use the Adobe Fonts folder:

Have you tried my suggestion from above?

Run this script in Macro window to close all paths:

for g in Font.glyphs:
	for l in g.layers:
		for p in l.paths:
			p.closed = True
  • Export without overlap removal, without hinting.
  • Export into the Adobe fonts folder (see above).
  • In AI, type your text, covert to outlines, and open the paths again by removing the closing segment, probably best with a script again, if you need to do it often.