I’m trying to Enable\Disable Delimited Source using below code ,It was stopped working suddenly but it was working earlier without putting IIQDisabled in CSV and Schema.
I would suggest check your Build Map Rule again and if issue still remains work with Sailpoint to troubleshot the rule by adding some logging statements.
If it was working properly and no changes made then I would suggest you to connect with SailPoint support as there might be any changes at Tenant level that impacted this Rule.
Also, I suggest you to check this in your other tenant Sandbox/PROD.