Aria Operations is displaying alerts indicating that certificates are about to expire, even if some certificates have been renewed and imported in Aria Operations
Aria Operations 8.x
The alerts are triggered because Aria Operations truststore contains either unrenewed certificates or older certificates (even if the corresponding endpoint has a new, valid certificate in Aria Operations)
Aria Operations flags certificates based on their stored expiry dates.
Review article Certificate overview for VMware Aria Operations section 'Adapter and authentication sources' for more information on endpoint certificates and potential caveats.