Understanding ScreenUpdating

I have an Auto_Open macro that I use to orientate the two sheets of the Workbook to

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and Call another macro that updates the values in a Range in one of the worksheets based on

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I was thinking I could

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and everything would be updated.

But if I do this, even the macro that updates the range values doesn't update the range. To make my Auto_Open update everything, I have to have

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Is Application.ScreenUpdating behaving differently because of Auto_Open ?

Here is my Auto_Open

Thanks for any insight.

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