- Plesk Onyx for Linux
Additional nginx directives defined at Service Plans > plan_name > Web Server are not applied to newly created subdomains of a subscription assigned to such service plan.
The behavior is confirmed as Plesk bug with ID PPPM-10041.
Until the fix becomes available, consider to create subdomains as domains. For example,
Go to Subscriptions > example.com > Add Domain and specify the required subdomain as full domain: