How to reference the code_click to a specific worksheet - excel

Question

How I can refer to Worksheets("Customers") without activating the worksheet in the below code?
Application.ScreenUpdating does not do the job, as there is still annoying flickering.
The code is working fine when I uncomment 'Worksheets("Customers").Activate
I want to perform all steps when Worksheets("Dashboard") is open.
I have tried "With ... End With" but no luck., also referencing Worksheets("Customers").Cells..... etc are not working. Its like code skipping through the code and goes straight to
"
If SearchRow = 2 Then
MsgBox "Customer Not Found", vbExclamation
Exit Sub
End If
"
I also have another code similar issue, that for some reason referencing not working as it should.
Just want to mention that I am using this code with the userforms and click buttons.
Any help will be appreciated.
Private Sub srCus_Click()
Application.ScreenUpdating = False
Dim RowNum As Long
Dim SearchRow As Long
RowNum = 2
SearchRow = 2
Worksheets("SearchCus").Range("A2:I100").ClearContents
'Worksheets("Customers").Activate
Do Until Worksheets("Customers").Cells(RowNum, 1).Value = ""
If InStr(1, Cells(RowNum, 3).Value, CusDB.Value, vbTextCompare) > 0 Then
Worksheets("SearchCus").Cells(SearchRow, 1).Value = Cells(RowNum, 1).Value
Worksheets("SearchCus").Cells(SearchRow, 2).Value = Cells(RowNum, 2).Value
Worksheets("SearchCus").Cells(SearchRow, 3).Value = Cells(RowNum, 3).Value
Worksheets("SearchCus").Cells(SearchRow, 4).Value = Cells(RowNum, 4).Value
Worksheets("SearchCus").Cells(SearchRow, 5).Value = Cells(RowNum, 5).Value
Worksheets("SearchCus").Cells(SearchRow, 6).Value = Cells(RowNum, 6).Value
Worksheets("SearchCus").Cells(SearchRow, 7).Value = Cells(RowNum, 7).Value
Worksheets("SearchCus").Cells(SearchRow, 8).Value = Cells(RowNum, 8).Value
Worksheets("SearchCus").Cells(SearchRow, 9).Value = Cells(RowNum, 9).Value
SearchRow = SearchRow + 1
End If
RowNum = RowNum + 1
Loop
If SearchRow = 2 Then
MsgBox "Customer Not Found", vbExclamation
Exit Sub
End If
ResultsDB.RowSource = "SearchResults"
'ThisWorkbook.Worksheets("Dashboard").Activate
Application.ScreenUpdating = True
End Sub

Answer 1

Thanks SJR, You were right with reference to all these Cells(RowNum, 1), I was always skipping one with InStr line. Thanks for the help and all suggestions. Reviewed code below.
Private Sub srCus_Click()
Application.ScreenUpdating = False
Dim RowNum As Long
Dim SearchRow As Long
RowNum = 2
SearchRow = 2
Worksheets("SearchCus").Range("A2:I100").ClearContents
'Worksheets("Customers").Activate
Do Until Worksheets("Customers").Cells(RowNum, 1).Value = ""
If InStr(1, Worksheets("Customers").Cells(RowNum, 3).Value, CusDB.Value, vbTextCompare) > 0 Then
Worksheets("SearchCus").Cells(SearchRow, 1).Value = Worksheets("Customers").Cells(RowNum, 1).Value
Worksheets("SearchCus").Cells(SearchRow, 2).Value = Worksheets("Customers").Cells(RowNum, 2).Value
Worksheets("SearchCus").Cells(SearchRow, 3).Value = Worksheets("Customers").Cells(RowNum, 3).Value
Worksheets("SearchCus").Cells(SearchRow, 4).Value = Worksheets("Customers").Cells(RowNum, 4).Value
Worksheets("SearchCus").Cells(SearchRow, 5).Value = Worksheets("Customers").Cells(RowNum, 5).Value
Worksheets("SearchCus").Cells(SearchRow, 6).Value = Worksheets("Customers").Cells(RowNum, 6).Value
Worksheets("SearchCus").Cells(SearchRow, 7).Value = Worksheets("Customers").Cells(RowNum, 7).Value
Worksheets("SearchCus").Cells(SearchRow, 8).Value = Worksheets("Customers").Cells(RowNum, 8).Value
Worksheets("SearchCus").Cells(SearchRow, 9).Value = Worksheets("Customers").Cells(RowNum, 9).Value
SearchRow = SearchRow + 1
End If
RowNum = RowNum + 1
Loop
If SearchRow = 2 Then
MsgBox "Customer Not Found", vbExclamation
Exit Sub
End If
ResultsDB.RowSource = "SearchResults"
'ThisWorkbook.Worksheets("Dashboard").Activate
Application.ScreenUpdating = True
End Sub