Linq Method Syntax Querying to include Navigational Property information EF Core 3

Question

I am trying to query and have the navigational property (the list) return with the correct number of items in it. Currently what I am doing, the list is always empty (Case_Users property in Case object for the example below) when it should not be.

I have these classes:

public class Case
    {
        public Case()
        {
            Create_Date = DateTime.Now;
        }
        [Key]
        public int Id { get; set; }

        [MaxLength(1000)]
        public string CaseNumber { get; set; }

        public ICollection<Case_Users> Case_Users { get; set; } = new List<Case_Users>();
    }
    public class Case_Users
    {
        public Case_Users()
        {
            Create_Date = DateTime.Now;
        }
        [Key]
        public int Id { get; set; }
        [ForeignKey("Case")] 
        public int CaseID { get; set; }
        public Case Case { get; set; }
       
        public string Role {get; set;}
    }

I want to make it so that I can query using the method syntax, starting with the Case and using its navigational property to get the data from its Case_Users navigational property entries, like this:

   var query = _context.Case.Include(c => c.Case_Users).ToList();

I am getting simply my list object returned, but the Case_Users list object is empty. Even though it should not be.

Is it possible to query based on the navigational property, and if so what is the syntax?