Conditional Formatting - New Card Visual - Ref Labels

Hi 

i have a new card visual in my report and have used small mutiples to show a measure by Dept, i have also created a referance label which shows the prior month value and also a details label to display the variance 

i have created a conditional formatting measure to highlight the background of the label green/red based on up or down on prior month 

when i apply this it highlights everything as green (See below) - the first 2 should be red, when i use the same CF measure in a matrix it works as expected - is this a known error with the new card? or am i missing something?

thanks in advance 

David