Exclude users with exempted status on learning alert

I'm trying to put a filter (expression) on our learning alerts that would exclude any users who have an assignment that is in "exempted" status from receiving the notifications. Currently users who have this status on a learning assignment are receiving notifications that the assignment is coming due or overdue even though it's in "exempted" status. I have tried using all of the following with no luck.

${assignmentStatus} <> 'ORA_ASSN_REC_EXEMPT'

${assignmentStatus} <> 'ORA_ASSN_REC_EXEMPTED'

${assignmentSubStatus} <> 'ORA_ASSN_REC_EXEMPT'

${assignmentSubStatus} <> 'ORA_ASSN_REC_EXEMPTED'