View to display list of members who checked a certain profile field

I have set-up a custom profile feild which is a checkbox (Profile: Pulmonary Hypertension Associated With HIV). I now want to list all members who have checked the checkbox.

I set up a view with the feild 'Surname, Name' (also custom) with a filter looking at the field Profile: Pulmonary Hypertension Associated With HIV, with the operator as EQUALS and the value set to YES.

Nothing shows up even though I know there are members whom have checked the profile field Profile: Pulmonary Hypertension Associated With HIV.

Any ideas what I am doing wrong?