Select a device with valid credentials from the list of Profiles, click on Validate Credentials and then click on Submit.
The credentials are indicated as valid. However, from that moment all equipments are no longer polled by the snmpcollector probe.
In order for the equipments to be polled again, the snmpcollector probe must be restarted
Release : 20.4
Component : UIM - SNMPCOLLECTOR 4.05, 4.06
Upgrade to SNMPCOLLECTOR 4.06T2 it addresses this issue. Download from attachment in ticket below.