Adding a non-google font

Can you share the PHP snippet you used to add the Fonts to the Customizer ?

ie. this part of the process:
https://docs.generatepress.com/article/adding-local-fonts/#adding-it-to-the-customizer

In the Child theme Functions.php

add_filter( 'generate_typography_default_fonts', function( $fonts ) {
$fonts[] = 'caviardreams';
return $fonts;
} );

So font name used here:

$fonts[] = 'caviardreams';

Must match the font-family added to your @font-face CSS

font-family: 'caviar_dreamsregular',

So replace your function with this:

add_filter( 'generate_typography_default_fonts', function( $fonts ) {
    $fonts[] = 'caviar_dreamsregular';
    $fonts[] = 'caviar_dreamsitalic';
    $fonts[] = 'caviar_dreamsbold';
    $fonts[] = 'caviar_dreamsbold_italic';
    return $fonts;
} );

Then you should see all 4 of your fonts in the customizer.... and selecting them should now work.

Thanks David,

Funny thing is, I tried that earlier without success. I am guessing there was more than one issue at play.
Anyway, once again you have nailed it. Now I can finally get some sleep.

Many thanks

Glad to hear that. And you're welcome