VNA gateway shows an operational status of down but is showing Administrative status Up.
It's also integrated with Spectrum which shows expected inventory and data without issue.
All supported Performance Management and VNA releases
Tenant Agnostic Data Collector configurations don't support VNA. Seen here under the Limitations section:
It states "Tenant-agnostic Data Collectors cannot host CA Mediation Manager (CAMM) or CA Virtual Network Assurance (CA VNA). For each tenant, a separate Data Collector is required for CAMM and CA VNA."