Entity Framework Core one to many related data navigation property is always empty - database

Question

I feel like I'm missing something obvious here; I'm using .Net 5 with Entity Framework Core. The problem is that the foreign key is correct, but the associated navigation property is always empty and has no data. Do I have to do something with the fluent framework, or do something special with my includes?
I have 3 simplified entities and a database context method in this example, the project is much too large to include entirely. In the method, CalendarEvents is a DbSet:
public class CalendarEvent: IJsonSerializable
{
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int Id { get; set; }
/// <summary>
/// Gets the personnel associated with this event
/// </summary>
public virtual List<SchedulePerson> SchedulePeople { get; set; } = new List<SchedulePerson>();
}
public class SchedulePerson : IJsonSerializable, ICloneable
{
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int Id { get; set; }
public int EmployeeId { get; set; }
public virtual Employee Employee { get; set; }
public virtual CalendarEvent AssociatedCalendarEvent { get; set; }
}
public class Employee : IJsonSerializable
{
[Key]
public int Id { get; set; }
public virtual List<SchedulePerson> AssociatedSchedulePeople { get; set; } = new List<SchedulePerson>();
}
public class DbContext : DbContext
{
public DbSet<CalendarEvent> CalendarEvents { get; set; }
public DbSet<SchedulePerson> SchedulePeople { get; set; }
public DbSet<Employee> Employees { get; set; }
public DbContext(DbContextOptions<VibrationContext> options): base(options)
{
}
public CalendarEvent GetEvent(int calendarEventId)
{
var currentCalEvent = this.CalendarEvents.Where(x => x.Id == calendarEventId);
var dummy1 = currentCalEvent.FirstOrDefault();
var dummy2 = currentCalEvent.Include(calEvent => calEvent.SchedulePeople).ToList();
var dummy3 = currentCalEvent.Include(calEvent => calEvent.SchedulePeople).ThenInclude(people => people.Employee).ToList();
return currentCalEvent.FirstOrDefault();
}
}
In this case Employee is the associated navigation property, and the associated key EmployeeId, is correct. For the moment I've added extra logic that will populate each employee per schedule person separately, manually based on the foreign key EmployeeId, when I get the event, but I'd rather not have to add logic like that each time. If that's something unavoidable then that's fine, but I'd like to do things properly and let Entity Framework Core handle as much as possible.
For additional context:
SchedulePerson -> CalendarEvent is a many-to-one relationship
Employee -> SchedulePerson is a many-to-one relationship
In other words a calendar event can contain many schedule persons, but a schedule person can only be associated with one calendar event.
Employee can be associated with many schedule persons, but each schedule person is only associated with one employee.
There should only be one employee for each real person, but there can be multiple SchedulePersons for each real person.
Thank you for your help and let me know if there is any more information I can provide.
Also if anything else looks bad or wrong in these code snippets please let me know.
Edit, this is what I have to do if I want to get the employees in my request:
private void UpdateEmployeeContents(CalendarEvent calendarEvent)
{
foreach (SchedulePerson person in calendarEvent.SchedulePeople)
{
person.Employee = this.Employees.Where(x => x.Id == person.EmployeeId).FirstOrDefault();
}
}