Hello,
I just had the same problem. After updating ESXi Hosts with the latest HPE Addon offline bundle, I got the exact message in checkmk.
I found out that with that HPE Addon the AMS (Agentless Mgmt Service) package for Gen9 was removed. I installed the VIB manually and got it working again. Still don’t know why it only happened on 3 of 10 servers as I updated via VUM.
maybe this info helps!