Can a singleton in spring have static methods?

Component and Service type beans and most of the other bean types are by default singleton.

In one of my code Pull requests, I declared a method as static in a Component as the method wasn't modifying any class level variables.

My code reviewer pointed out that since the class is anyways a Singleton and is going to have a single reference, he said it was unnecessary to make the method static, but rather make it a public method.

Which way is the correct way of writing code as most of the classes in my application are Singletons?