Worksheet formula auto calculation

[insomniac53]

I want the formulas on a couple of sheets to perform automatically when that sheet is opened or switched to from another sheet. The Calculations option is already set to automatic.
I have tried this code on the sheets in question:

Private Sub Worksheet_Activate()
    'Application.Volatile
    'ActiveSheet.EnableCalculation = True
    ThisWorkbook.Sheets("Sheet Name").Calculate
End Sub

also

    ActiveSheet.Calculate

Nothing. The formulas only operate when I click "Calculate Now" or "Calculate Sheet"
Can anyone advise?

 

[sxhall]

Have you tried...

Application.Calculation = xlAutomatic

I'm guessing it is set to xlmanual somewhere in the code and then not reset to xlautomatic at the end.

 

[insomniac53]

Thank you, but no, I've checked and xlmanual is never used. I tried xlautomatic anyway but it made no difference. I wonder whether it is something to do with the subroutine Activate. If the worksheet is already the active sheet, then the code won't execute. Still working on it.