SQL: Login 'abc' owns one or more databases(s)... Even though I just dropped those roles

Question

I'm trying to remove an SQL login with the following commands:

USE [myDB]
GO
ALTER ROLE [db_owner] DROP MEMBER [abc]
GO
USE [myDB]
GO
DROP USER [abc]
GO
USE [master]
ALTER SERVER ROLE [sysadmin] DROP MEMBER [abc]
GO
USE [master]
DROP LOGIN [abc]
GO

But SQL returns the following Error: Login 'abc' owns one or more database(s). Change the owner of the database(s) before dropping the login.

There are no other (Non-System-)Databases present on the server and i litterally just dropped the login from role DB_owner - what is going on?