Freemius - Free plugin updates blocked if premium and free versions do not match

gist.php

<?php

// Functions that you'll need
function get_free_version() { /* ... */ }
function get_premium_version() { /* ... */ }
function is_free_plugin($plugin_basename) { /* ... */ }

// Filter the value of the transient where WordPress stores pending updates
add_filter('site_transient_update_plugins', function ($value) {
    // Only proceed if the transient has responses from update servers
    if (is_object($value) && !empty($value->response)) {
        $f_ver = get_free_version();
        $p_ver = get_premium_version();

        // If the free version is older than the premium version ...
        if (version_compare($f_ver, $p_ver, '<')) {
            // Strip out all entries for the free version from the response array
            $value->response = array_filter($value->response ?? [], function ($response) {
                return !is_free_plugin($response->plugin);
            });
        }
    }

    return $value;
});