A long time ago I report problem with snmpcollector probe, but later we realize that it is problem with spectrumgtw probe and it will be fixed in next release (20.41)
I testedit today and there is still same problem with migrating snmp credentials from Netops to UIM through spectrumgtw. I added 2 devices to Spectrum Global Collection and manually started Inventory synchronization through spectrumgtw. It added 2 devices in the Operator Console so I start "Query discovery server" through snmpcollector and both devices were discovered with bad credentials.
Discovery Failed - Credentials Invalid or device is unreachable.
I manually typed in the Community String for the 2nd device, save settings and it started to work.
Upgraded the snmpcollector probe to version 4.14 and verified the issue was resolved.
Please refer to the doc as the issue is mentioned as a part of the snmpc v4.14 release