Fonts not showing up because of language metadata

Hello community,

Basically my problem is that when I use my mac in Dutch (Nederlands), many fonts that I install do not show up in apps such as Pages. However, I noticed that, when changing the system language to English, all fonts show up nicely. Also in the separate font chooser (cmd-T) the non-working fonts are present.

Screenshot 1: The font 'Ghost Stories' does not show up in my fonts list in Pages.

Screenshot 2: All fonts are displayed correctly in the advanced font chooser.

So I dug into Font Book and noticed a smart set (which can't be deleted) called 'Nederlands', in which are all the fonts that display in my apps. This smart set bases its 'smartness' on the metadata of the font: the 'language'. And, as I compared with other fonts that work well, almost all third party fonts that I try to install support all the languages the others do, except for Nederlands.

Screenshot 3: Languages of a perfectly fine working font, Gill Sans (Taal = Language)

Screenshot 4: The same data of the non-working font

I hope you understand my problem and know how to do one of the following:

1) Make apps show all fonts (not only the ones in my language) by default,

2) Make MacOS ignore language of fonts or place the fonts in the smart set by hand,

3) Change font properties so it supports my language.

4) ???

Thanks in advance for thinking along. Feel free to ask for more information when necessary.

Robni7

My mac runs on 10.11.6, 2.5GHz 8GB 256GB 13MBP (Late 2012).