Can't calculate a threshold value through a Function and a Sorting procedure of an Array

I am trying alternative methods for calculating a minimum threshold value (0.05) using a Function, a Sort procedure, and arrays (CoursAction)

However, I get a message that an array is expected for the Var Function.

Does anyone have a guess what could the problem be?

See the attachment below.

Option Explicit
Option Base 1

Sub Performance()
Dim N As Long
Dim EnsembleActions As Range
Dim Nb_Actions As Integer
Dim Action As Range
Dim CoursAction As Range
Dim i As Integer
Dim SharpeRatio As Double
Dim TauxRf As Double
Dim RendsEcart As Double
Dim NomAction As String
Dim ValeursAction() As Variant
Dim NB As Integer
Dim alpha As Double
Dim VarA As Double

    With Worksheets("Actions")
        Nb_Actions = .Cells(1, Columns.Count).End(xlToLeft).Column
    End With

    With Worksheets("Actions")
        Set EnsembleActions = .Range(.Cells(2, 1), .Cells(.Rows.Count, Nb_Actions).End(xlUp))
    End With

    For Each Action In EnsembleActions.Columns
        i = i + 1
        Set CoursAction = Action

        TauxRf = Worksheets("Performance").Cells(2, 2).Value
        RendsEcart = WorksheetFunction.StDev(CoursAction)
        
         NB = WorksheetFunction.Count(CoursAction)
     
       Dim alpha As Double
       Dim Var As Double
       
        alpha = Worksheets("Performance").Cells(3, 2).Value
        
        VarA = VarB(CoursAction, alpha)
        
    
        NomAction = Worksheets("Actions").Cells(1, i).Value

        With Worksheets("Performance")
            .Cells(4 + i, 1) = NomAction
         
            .Cells(4 + i, 2) = VarA
            
        End With
    Next Action

End Sub

Function VarB(Rendements As Range, A As Double)
    Dim N As Double
    Dim i As Integer
    Dim CoursAction As Double
    
    CoursAction = 0
    
    N = WorksheetFunction.Count(Rendements)

    For i = 1 To N
        CoursAction = CoursAction + Rendements(i)
    Next i
    
    'We sort the array
    Call Tri1(CoursAction)
    
    VarB = CoursAction(Int(N * A)) 'A ici correspond au Alpha
    
    
End Function

Sub Tri1(plaga As Variant)
Dim ligne_Deb As Long
Dim ligne_Fin As Long

    ligne_Deb = LBound(plaga)
    ligne_Fin = UBound(plaga)

    Dim i As Long, J As Long
    Dim tmp As Long

    For i = ligne_Deb To ligne_Fin - 1
        For J = ligne_Fin To i + 1 Step -1
            If plaga(J, 1) < plaga(J - 1, 1) Then
                tmp = plaga(J, 1)
                plaga(J, 1) = plaga(J - 1, 1)
                plaga(J - 1, 1) = tmp
            End If
        Next J
    Next i

End Sub

I've had a look at the code and as far as I can see the problem is that Var isn't a VBA function, you can access it with Application.WorksheetFunction.Var.

Is this all in one module? I note that Sub Performance has a variable Var (double) dimensioned, then, a couple of statements later you call Var the function. I wonder if what you are seeing is a naming conflict, where VBA is having trouble resolving the double variable Var and the function Var. I would try changing the name for one of those to something unique, to avoid the potential conflict.