Enablement expression for custom attribute

Hi,

I am trying to disable a button once a custom attribute reaches a certain value. I see my attribute in the fields menu of the expression and i set it equal to that value but the button is just always disabled. if i set it to not equal that value then the button never gets disabled. I am not sure what the issue as a i think i am setting the correct expression. What steps can i take to figure out why this is not working?