VB Autofilter alongside IF AND

Hopefully my last request for help on this workbook.

In the attached workbook, in Column J I have the following statement

Formula:

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this then uses the following VB

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this all works great EXCEPT for the following issue. If I add a new date into Column L (L11), I want J12 to revert to "" rather than "Hide", which in my thinking should then make Row 12 visible again giving me the opportunity to add a date into L12 if someone is off work for anything other than sickness.

It DOES work if I re-enter the date - in this case B34, the Autofilter runs again.