Fatal error on manual process php 8.1

Fatal error: Uncaught Error: array_filter(): Argument #1 ($array) must be of type array, string given
in /home/example/example.com/wp-includes/post.php on line 4155

Call stack:

1. array_filter()
   wp-includes/post.php:4155
2. wp_insert_post()
   wp-content/plugins/postie/postie-message.php:641
3. PostieMessage::save_post()
   wp-content/plugins/postie/postie-message.php:159
4. PostieMessage::process()
   wp-content/plugins/postie/postie.class.php:211
5. Postie::fetch_mail()
   wp-content/plugins/postie/postie.class.php:89
6. Postie::get_mail()
   wp-content/plugins/postie/postie-api.php:74
7. postie_get_mail()
   wp-content/plugins/postie/config_form.php:33
8. require_once()
   wp-content/plugins/postie/postie.php:302
9. PostieInit::postie_show_config_page()
   wp-includes/class-wp-hook.php:308
10. WP_Hook::apply_filters()
    wp-includes/class-wp-hook.php:332
11. WP_Hook::do_action()
    wp-includes/plugin.php:517
12. do_action()
    wp-admin/admin.php:259

I had this all working fine but have since moved to php8.1 from 7.4 which might be the cause of the above. Any insight as to what the issue might be? Same issue with current and prior rolled back version of Postie. Thanks