One site without favoris in network cause misfunction for other site

I have an error in my network wordpress. I have 3 sites on my network, the first one without favorites, the other with favorites. And i have some issue

First in the function get_user_favorites_count

Warning: Undefined array key “site_id” in …/favorites/app/Helpers.php on line 96

I fix this

if ( $site_favorites['site_id'] == $site_id && isset($site_favorites['posts']) ) return $site_favorites['posts'];

with

if ( !empty($site_favorites['site_id']) && $site_favorites['site_id'] == $site_id && isset($site_favorites['posts']) ) return $site_favorites['posts'];

And a second issue with the_favorites_button
Warning: Undefined array key “site_id” in /var/www/html/wordpress/toulouse-attractivité-mb/assets/plugins/favorites/app/Helpers.php on line 113

I fix this

if ( $site_favorites['site_id'] !== $site_id ) continue;

with

if ( !empty($site_favorites['site_id']) && $site_favorites['site_id'] !== $site_id ) continue;

This modification fix the warning but trigger an error

Fatal error: Uncaught TypeError: in_array(): Argument #2 ($haystack) must be of type array, null given in /var/www/html/wordpress/toulouse-attractivité-mb/assets/plugins/favorites/app/Entities/User/UserRepository.php:189 Stack trace: #0 /var/www/html/wordpress/toulouse-attractivité-mb/assets/plugins/favorites/app/Entities/User/UserRepository.php(189): in_array()

I fix this

if ( in_array($post_id, $favorites) ) return true;

with

if ( is_array( $favorites) && in_array($post_id, $favorites) ) return true;

And after this modification, everything work fine.

Maybe I miss something, a setting to avoid this problem, but if not, maybe it’s should be a good idea to solve this issue