Why does the editor not display the fonts in the referenced ttf file?

Questions
1

In the ‘GUI font’ example Defold examples
In the Defold editor (Linux 1.14.0):
When I open test_ar.json all the (Arabic) characters are correctly displayed.
When I run the game, all characters are correctly displayed.
when I open noto_ar.font none of the characters in the json file are displayed, why is this?
(clicking all-characters, in properties, does not add them)