Many to many self reference with multiple key arguments

Question

I can't seem to figure this one out. I tried a solution along the lines of information found here: ASP.Net Forum, but that issue is different enough to not work for me.

• This does not work either: Entity Framework many-to-many self-reference (HasMany+WithMany does not exist in Efcore)

• nor this: Entity Framework Core: many-to-many self referencing relationship

• nor this: Many to Many Self referencing relationship

This is my scenario:

public class ApplicationUser
{
    public int Id { get; set; }
    public ICollection<CustomerContractorBan> Bans { get; set; }
}


public enum BanType
{
    Contractor,
    Customer
}

public class CustomerContractorBan
{
    public BanType BannedBy { get; set; }

    [ForeignKey(nameof(CustomerId))]
    public ApplicationUser Customer { get; set; }

    public int CustomerId { get; set; }

    [ForeignKey(nameof(ContractorId))]
    public ApplicationUser Contractor { get; set; }

    public int ContractorId { get; set; }

    public DateTimeOffset Time { get; set; }
}


    /// <inheritdoc />
    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<CustomerContractorBan>().HasKey(d => new { d.ContractorId, d.CustomerId, d.BannedBy });

        modelBuilder.Entity<CustomerContractorBan>()
            .HasOne(d => d.Contractor)
            .WithMany(d => d.Bans)
            .HasForeignKey(d => new { d.ContractorId })
            .OnDelete(DeleteBehavior.Restrict);

        modelBuilder.Entity<CustomerContractorBan>()
            .HasOne(d => d.Customer)
            .WithMany(d => d.Bans)
            .HasForeignKey(d => new { d.CustomerId })
            .OnDelete(DeleteBehavior.Restrict);
    }

What i am trying to achieve:

• User 1 should be able to ban user 2 With BannedBy=Contractor
• User 2 should be able to ban user 1 With BannedBy=Customer

The exception i am currently getting is:

Cannot create a relationship between 'ApplicationUser.Bans' and 'CustomerContractorBan.Customer', because there already is a relationship between 'ApplicationUser.Bans' and 'CustomerContractorBan.Contractor'. Navigation properties can only participate in a single relationship

Am i doing this wrong or is this a limitation of efcore 2.1? I've seen similar code resolve similar issues. However in my case i can't seem to call the modelbuilder twice without getting an exception.

PS: This used to work until i added BannedBy to the properties+keys. Obviously either participant should be able to ban each other.