I've worked around it by changing the WHERE clause to what's shown below. But it's not ideal

AND

BUILTIN.DF(t.status) NOT IN (

'Purchase Order : Pending Supervisor Approval',

'Purchase Order : Rejected by Supervisor',

'Purchase Order : Fully Billed',

'Purchase Order : Closed'

)

Unfortunately, this is a known issue and the way you got around it is the workaround for now