I can not add SNMP monitor on device based on SNMP V2

I'd like to use Kaseya Network Monitor 4.1 to add SNMP monitor to ceragon FibeAir IP-10 system. 

When I configured the system based on SNMP V1, KNM works well by adding SNMP monitor.

But, when I configured the system based on SNMP V2, I can not add SNMP monitor on it due to all the OIDs are blink.

What is the root cause of it?

Thanks.