Seems NISS bug is fixed now?
(make sure you use PT version of any portal - EN version may not be tested to same rigour)
AIMA Update: Renewal Portal Accepts Applications Without NISS (November 2025)
AIMA… has officially updated the Residence Permit Renewal Portal, allowing applicants to submit their renewal requests even without a Social Security Identification Number (NISS) .
This important change, launched in November 2025, simplifies the process for many residents whose NISS (Social Security Number) has not yet been integrated into the AIMA system. From now on, you can submit your residence permit renewal online even if your NISS is not registered.