Hello,
I also faced this problem in 2021 and at the end, as we have only one device affected, I decided to ignore it.
CheckMK 2.0.0p5 - SNMPv3 - Contexts to use in requests
Actually, I suspect could be a kind of bug because it doesn’t work no matter which “Section name” you chose. Snmpwalk instead works fine.
Last reply to this topic was 20 days ago so I would like to join it to see if someone can help us.
Mattia