Copying and pasting from one workbook to another doesn't work - excel

Question

I'm trying to do a simple thing. The code is supposed to copy specific ranges from one workbook to another but when I run the following code copying doesn't occur - nothing happens. (copying happens in the last part of Sub). I suspect it might be a problem with worksheets/workbooks but I'm really new into VBA so it's hard to say for me...
Function getHeaderRange(searched As String, ws As Worksheet) As Range
Dim colNum
Dim cellLength
colNum = WorksheetFunction.Match(searched, ws.Range("5:5"))
cellLength = ws.Range(ws.Cells(5, colNum), ws.Cells(5, colNum)).MergeArea.Count
Set getHeaderRange = Range(ws.Cells(6, colNum), ws.Cells(6, colNum + cellLength - 1))
End Function
Function getDataRange(searched As String, hRange As Range) As Range
Dim column: column = WorksheetFunction.Match(searched, hRange) + hRange.column - 1
Set getDataRange = Range(Cells(6, column), Cells(6, column))
Debug.Print (hRange.Worksheet.Parent.Name & "Sheet: " & hRange.Worksheet.Name)
Set getDataRange = getDataRange.Offset(1, 0)
Set getDataRange = getDataRange.Resize(8)
End Function
Sub main()
Dim srcWs As Worksheet: Set srcWs = Workbooks("Period end open receivables, step 5").Sheets(1)
Dim trgWs As Worksheet: Set trgWs = ThisWorkbook.Sheets("Obiee")
Dim searched As String
Dim hSearched As String
searched = "Magazines, Merchants & Office"
Dim srcRange As Range: Set srcRange = getHeaderRange(searched, srcWs)
Dim trgRange As Range: Set trgRange = getHeaderRange(searched, trgWs)
Dim cocd() As Variant
Dim i As Integer
cocd = getHeaderRange("Magazines, Merchants & Office", trgWs)
For i = 1 To UBound(cocd, 2)
hSearched = cocd(1, i)
getDataRange(hSearched, srcRange).Copy
getDataRange(hSearched, trgRange).PasteSpecial xlPasteValues
Next i
End Sub
When I change last lines to:
For i = 1 To UBound(cocd, 2)
hSearched = cocd(1, i)
srcWs.Activate
getDataRange(hSearched, srcRange).Copy
trgWs.Activate
getDataRange(hSearched, trgRange).Select
ActiveSheet.Paste
Next i
It works just fine but I really would like to avoid this approach and find out what's wrong with the first one. Help really appreciated!
Edit: I'm including a to screenshots of workbooks (1. srcWb, 2. trgWb)
The file is huge and differentiated but in this cut they are the tables are the same.

Answer 1

Your ranges aren't fully qualified..
When they're not qualified, Excel will guess which worksheet the range in question resides on, usually using the currently active worksheet. That's why your workaround works as you change the active worksheet.
This line needs to be fully qualified:
cellLength = Range(ws.Cells(5, colNum), ws.Cells(5, colNum)).MergeArea.Count
So it'll become:
Function getHeaderRange(searched As String, ws As Worksheet) As Range
Dim colNum
Dim cellLength
colNum = WorksheetFunction.Match(searched, ws.Range("5:5"))
cellLength = ws.Range(ws.Cells(5, colNum), ws.Cells(5, colNum)).MergeArea.Count
Set getHeaderRange = ws.Range(ws.Cells(6, colNum), ws.Cells(6, colNum + cellLength - 1))
End Function
Also, this line is not qualified at all:
Set getDataRange = Range(Cells(6, column), Cells(6, column))
So it'll become:
Function getDataRange(searched As String, hRange As Range) As Range
Dim column: column = WorksheetFunction.Match(searched, hRange) + hRange.column - 1
Dim ws As Worksheet: Set ws = hRange.Worksheet
Set getDataRange = ws.Range(ws.Cells(6, column), ws.Cells(6, column))
Debug.Print (ws.Parent.Name & "Sheet: " & ws.Name)
Set getDataRange = getDataRange.Offset(1, 0)
Set getDataRange = getDataRange.Resize(8)
End Function
As per my comment below, to radically speed things up, I'd recommend removing these two lines from Main():
getDataRange(hSearched, srcRange).Copy
getDataRange(hSearched, trgRange).PasteSpecial xlPasteValues
and replacing them with:
getDataRange(hSearched, trgRange).Value = getDataRange(hSearched, srcRange).Value