Mismatched Stable Tag: 4.5 != 4.5.1. The Stable Tag in your readme file does not match the version in your main plugin file. Your Stable Tag is meant to be the stable version of your plugin, not of WordPress. For your plugin to be properly downloaded from WordPress.org, those values need to be the same. If they're out of sync, your users won't get the right version of your code.

Process completed with exit code 1.

Detected usage of meta_key, possible slow query.

Detected usage of meta_query, possible slow query.

Processing form data without nonce verification.

Processing form data without nonce verification.

$_POST['syndication_urls'] not unslashed before sanitization. Use wp_unslash() or similar

Detected usage of a non-sanitized input variable: $_POST['syndication_urls']

error_log() found. Debug code should not normally be used in production.

$_POST['syn_metabox_nonce'] not unslashed before sanitization. Use wp_unslash() or similar

Detected usage of a non-sanitized input variable: $_POST['syn_metabox_nonce']