Layout 2019.2 keeps refusing to add installed fonts to the fontlist. When updating a set of Ubuntu with bold for example, through a workaround (choose medium > rightclick-bold) it works, but after saving the settings are gone, because the fonts will not show up.
IS it me or is it a bug.?
I started off by wondering how you are using LayOut under Linux, but then realized that Ubuntu may be a font name in this case.
The font, from this page:
https://design.ubuntu.com/font/
works for me. Including Bold, and it shows up in LayOut right away.