Autofilter is not filtering.

[Celtlink]

Hello,
Novice level with excel, so please excuse me if I missing something very simple.
I have sheet Mraw containing all my data. I have sheet Materials where I want the filtered data to be shown.
I have the following macro code working of a command button.

Sub FINDMAT()


    Sheets("Mraw").Range("A1").CurrentRegion.AdvancedFilter Action:=xlFilterCopy, _
        CriteriaRange:=Sheets("Materials").Range("L2:L3"), CopyToRange:=Range("Materials!Extract"), _
        Unique:=False
End Sub

With no text into sheet Materials! L3 it returns all data to Materials sheet. If I insert any text in sheet Materials! L3 it always returns no data.
I have checked the code and tried redoing on new sheets etc, but still cannot understand what my solution is.

Thanks in advance for help cheers!

 

[Celtlink]

All good managed to resolve. Had to extend the Criteria Range to include all header range! ie "L2:M3" all done working