Just been having a look, found a free FarmHouse that is otf. Not the same as your installation but does exhibit a 'changed' font name in Gimp: https://i.imgur.com/TWVmndb.jpg Indicates a less than wonderful font structure.
..but installed in Windows, fonts only shows the same as previously. Uninstall from Win fonts and the font goes from Gimp.
The only strange thing, with the fonts installed, a Windows search for *.otf does not show anything in C:\ https://i.imgur.com/8Zc5Q4K.jpg but then I am a linux user and might be missing something.
Gimp installed in F: ? Have you tried renaming F:\Program Files\GIMP 2\var\cache\fontconfig to disable it. Guessing it contains hard links to non-existent files.
edit: That is strange, I do not seem to have a ..\Program Files\GIMP 2\var\ on my installation.
edit again: That reported as a bug https://gitlab.gnome.org/GNOME/gimp/issues/2574
edit once more: Gimp picky about fonts
This the Nubian font you referenced. nubian-shadow uses system default. https://i.imgur.com/n2wv0Pw.jpg Probably can be fixed with FontForge.
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as an example Nubian-Shadow re-built with fontforge. (zipped & attached Better give it a try in Win10 https://i.imgur.com/42C6KVY.jpg )
If you paid money for Farmhouse, then get hold of the author and ask for a refund or a fix
..but installed in Windows, fonts only shows the same as previously. Uninstall from Win fonts and the font goes from Gimp.
The only strange thing, with the fonts installed, a Windows search for *.otf does not show anything in C:\ https://i.imgur.com/8Zc5Q4K.jpg but then I am a linux user and might be missing something.
Gimp installed in F: ? Have you tried renaming F:\Program Files\GIMP 2\var\cache\fontconfig to disable it. Guessing it contains hard links to non-existent files.
edit: That is strange, I do not seem to have a ..\Program Files\GIMP 2\var\ on my installation.
edit again: That reported as a bug https://gitlab.gnome.org/GNOME/gimp/issues/2574
edit once more: Gimp picky about fonts
This the Nubian font you referenced. nubian-shadow uses system default. https://i.imgur.com/n2wv0Pw.jpg Probably can be fixed with FontForge.-----
as an example Nubian-Shadow re-built with fontforge. (zipped & attached Better give it a try in Win10
https://i.imgur.com/42C6KVY.jpg )If you paid money for Farmhouse, then get hold of the author and ask for a refund or a fix