Favicon not showing in Google search results

I always use Real Favicon Generator to generate favicon images for my websites, and have never had any issue.

Their favicon checker did have several issues come up for your site:
https://realfavicongenerator.net/favicon_checker?protocol=https&site=discovernavarra.com.

I suspect that the redirect on favicon.ico may be the issue, though I do not know for sure.

I never use a provided theme’s favicon system, always implement it manually with images in root and an mu-plugin.

Files in root:

android-chrome-192x192.png
android-chrome-512x512.png
apple-touch-icon.png
browserconfig.xml
favicon-16x16.png
favicon-32x32.png
favicon.ico
mstile-150x150.png
site.webmanifest

mu-plugins/favicons.php

add_action( 'wp_head', static function () {
    ?>

    <link rel="apple-touch-icon" sizes="180x180" href="/apple-touch-icon.png">
    <link rel="icon" type="image/png" sizes="32x32" href="/favicon-32x32.png">
    <link rel="icon" type="image/png" sizes="16x16" href="/favicon-16x16.png">
    <link rel="manifest" href="/site.webmanifest">
    <meta name="msapplication-TileColor" content="#da532c">
    <meta name="theme-color" content="#ffffff">

    <?php
} );