NSX-T app health is affected" Aria Operations 8.18x
The NSX-T app health adapater is associated with the VMware Infrastructure Health (VIH) object/adapater which should be checked for the collection status via Configurations > Inventory Management.
If the status is collecting and healthy, restart the VIH adapater via KB: VMware Infrastructure Health (VIH) Adapter is missing from Integrations source
If restarting the adapater does not help, check the adapater.log for the VIH adapater via > Control Panel > Support logs > Cloud Proxy associated with the VIH adapater > VMwareInfraHealthAdapater.log