This is intentional. In the past, many users removed themselves ranks or altered permissions, which required manual recovery on our end. To prevent this in the future, all newly created communities now include this “safety lock”.
If you want to use custom icons, you need to create new groups and keep the Owner group icon unchanged.
We do not recommend this for new TeamSpeak users:
But like mentioned below you can daily drive a different identity with just the Server Admin permissions.
Please keep in mind that if you somehow manage to delete this one or loos it. You may loose full access to your server. So proceed with caution and only if you know how identities and permissions on TeamSpeak work.