MemberNotNullWhen() attribute won't work with properties in the base class?

Question

I have a method that guarantees a property is not null when the method returns true.

[MemberNotNullWhen(true, "CurrentLine")]
public bool Read()
{
}

This works fine.

But I also have a class that derives from this class, which has a method that calls the Read() method above. That method also guarantees that the same property is not null when the method returns true.

But when I apply the same attribute to the method in the derived class, I get an error.

Warning CS8776 Member 'CurrentLine' cannot be used in this attribute.

There is no information available on this warning. Does anyone know why I can't use this attribute with a property from a base class?