Add comments to records - C# 9

I'm looking for a way to add comments on record properties, in C# 9 When I try this code :

public record Person
{
    /// <summary>
    /// Gets the first name.
    /// </summary>
    public string FirstName { get; init; }
    
    /// <summary>
    ///  Gets the last name.
    /// </summary>
    public string LastName { get; init; }
}

I get this warning :

Non-nullable property 'FirstName' must contain a non-null value when exiting constructor. Consider declaring the property as nullable. When I try :

public record Person(string firstName, string lastName);

I get this warning:

Missing XML comment for publicly visible type or member 'Person.firstName'

This does not work either.

/// <summary>
/// Person.
/// </summary>
/// <param name="FirstName">Get the first name.</param>
/// <param name="LastName">Get the last name.</param>
public record Person(string FirstName, string LastName);

Gives warning:

XML comment has a param tag for 'FirstName', but there is no parameter by that name