This is driving me insane!

I have a ComboBox with two Text Boxes that update two separate cells on a worksheet with dates. The dates are used by the advanced filter as the Criteria range to filter two separate ranges From: and To:

Each TextBox is formatted as follows:

[ComboBox1.Value = Format(CDate(ComboBox1.Text), "dd-mmm-yy")]

The Criteria range cells refer to each one of the updated cells with the following formula:

=">="&DATE(YEAR(ptrAdvFilterFrom),MONTH(ptrAdvFilterFrom),DAY(ptrAdvFilterFrom))
and
="<="&DATE(YEAR(ptrAdvFilterTo),MONTH(ptrAdvFilterTo),DAY(ptrAdvFilterTo))

the result in the Criteria range in each instant is the date serial number i.e. >=40598

When I run the VBA code the Advanced Filter does not work. However, if I type the the same dates manually in the cells the Advanced Filter performs correctly.

Can someone assist please!

Thanks/sglxl