EF Core Nullable Foreign Key Relationship

        x.HasOne(t => t.Client)
            .WithMany()
            .HasForeignKey(f => f.ClientId)
            .OnDelete(DeleteBehavior.Restrict)
            .IsRequired(false);

System.InvalidOperationException: The client projection contains a reference to a constant expression of 'Common.Identifier'. This could potentially cause a memory leak; consider assigning this constant to a local variable and using the variable in the query instead.

        ClientId = namelessParameter{0}.ClientId == null ? 00000000-0000-0000-0000-000000000000 : new Identifier{ Value = (Guid)namelessParameter{0}.ClientId.Value }

public sealed class IdentifierConverter() : ValueConverter<Identifier, Guid>(id =>      id.Value,
    value => value);

    protected override void ConfigureConventions(ModelConfigurationBuilder configurationBuilder)
    {
        configurationBuilder
            .Properties<Identifier>()
            .HaveConversion<IdentifierConverter>();
    }