My formula is not changing a 'month' when using named range

Hi all,

mY TAB DATA_Dashboard, cell D4 should be changing the value currently listed as january to the month selecteed from the list on the left.. under b16 can anyone advise why cell D4 does not change values.. ie it says summary for month january. I want it to show summary for month july, if july is selected from the list on the left

thank you

Name manager

List_Month
=Lists!$D$4:$D$15

TAB DATA_Dashboard, cell D4

="Summary for month "&Lists!D2