C# GroupBy Trouble

As of now, I am trying to create a list that groups based on certain criteria and then display that list in the view.

I have two database tables and one is an association table.

First Table

public partial class InitialTraining
{
    public InitialTraining()
    {
        InitialTrainingAssociations = new HashSet<InitialTrainingAssociation>();
    }
    public int Id { get; set; }

    [ForeignKey("MedicInfo")]
    public int TfoId { get; set; }

    [ForeignKey("InstructorInfo")]
    public int? InstructorId { get; set; }

    [ForeignKey("PilotInfo")]
    public int? PilotId { get; set; }

    public DateTime DateTakenInitial { get; set; }

    public decimal FlightTime { get; set; }

    public bool Active { get; set; }

    [StringLength(2000)]
    public string Narrative { get; set; }

    [Required]
    [StringLength(20)]
    public string TrainingType { get; set; }

    [ForeignKey("CodePhase")]
    public int PhaseId { get; set; }

    [ForeignKey("PhaseTrainingType")]
    public int PhaseTrainingTypeId { get; set; }
    public string EnteredBy { get; set; }
    public DateTime? EnteredDate { get; set; }

    public virtual MedicInfo MedicInfo { get; set; }
    public virtual MedicInfo InstructorInfo { get; set; }
    public virtual MedicInfo PilotInfo { get; set; }
    public virtual Code_Phase CodePhase { get; set; }
    public virtual Code_PhaseTrainingType PhaseTrainingType { get; set; }
    public virtual ICollection<InitialTrainingAssociation> InitialTrainingAssociations { get; set; }
}

Second Table (Association Table)

public class InitialTrainingAssociation
{
    public int Id { get; set; }
    [ForeignKey("InitialTraining")]
    public int InitialTrainingId { get; set; }
    [ForeignKey("CodePerformanceAnchor")]
    public int? PerformanceAnchorId { get; set; }
    [ForeignKey("GradingSystem")]
    public int? GradingSystemId { get; set; }
    public virtual AviationMedicTraining.CodePerformanceAnchor CodePerformanceAnchor { get; set; }
    public virtual InitialTraining InitialTraining { get; set; }
    public virtual GradingSystem GradingSystem { get; set; }
}

Here is my GroupBy in C#.

// get list of initial training record ids for statistics
var lstInitialTrainings = db.InitialTrainings.Where(x => x.TfoId == medicId && x.Active).Select(x => x.Id).ToList();

// get list of initial training performance anchors associated with initial training records
var lstPerformanceAnchors = db.InitialTrainingAssociations
    .Where(x => lstInitialTrainings.Contains(x.InitialTrainingId)).GroupBy(t => t.PerformanceAnchorId)
    .Select(s => new MedicStatistic()
    {
        PerformanceAnchorName = db.CodePerformanceAnchor.FirstOrDefault(v => v.Id == s.Key).PerformanceAnchor,
        AnchorCount = s.Count()
    }).ToList();

My Goal

Obviously from my code I want to group by the performance anchor in the association table, but I need more information from the Initial Training table to include in my ViewModel MedicStatistic, but I am having trouble figuring out the best way to do it.

My overall goal is to be able to get the most recent time a performance anchor was completed from the Initial Training table.

Visual

Initial Training Table (not all fields were captured in snippet b/c they're not important for the purpose of this question)

Initial Training Association Table

What I expect

So, from the pictures provided above as you can see there are multiple 1's for performance anchor id's in the association table, but they each have different InitialTrainingId. So, this specific performance anchor has been done multiple times, but I need to get the most recent date from the Initial Training table. Also, I need to get the corresponding grade with the anchor from the Grading System table, based on the most recent date.

So, for the performance anchor that equals 1.. I would want the grade that corresponds to the InitialTrainingId of 17 because that record was the most recent time that the performance anchor of 1 was done.

If you have any questions please let me know.