How many OIDs can an AP79xx PDU receive over SNMPv3?

[ElectricAvenue]

I'm writing some scripts that communicate with our PDUs.

I just noticed that if I send more than 4  OIDs at once, the PDU doesn't respond.

Same behavior in Python+pySNMP and with snmpset.

For example, this works fine:

snmpset -v3 -u user2 -l authPriv -a MD5 -A "1234567890123456" -x DES -X "1234567890123456" 192.168.120.177 \
1.3.6.1.4.1.318.1.1.12.3.3.1.1.4.10 i 2 \
1.3.6.1.4.1.318.1.1.12.3.3.1.1.4.11 i 2 \
1.3.6.1.4.1.318.1.1.12.3.3.1.1.4.12 i 2 \
1.3.6.1.4.1.318.1.1.12.3.3.1.1.4.13 i 2 \

SNMPv2-SMI::enterprises.318.1.1.12.3.3.1.1.4.11 = INTEGER: 2
SNMPv2-SMI::enterprises.318.1.1.12.3.3.1.1.4.11 = INTEGER: 2
SNMPv2-SMI::enterprises.318.1.1.12.3.3.1.1.4.12 = INTEGER: 2
SNMPv2-SMI::enterprises.318.1.1.12.3.3.1.1.4.13 = INTEGER: 2

But this may or may not execute, and always returns "No SNMP response received before timeout".

snmpset -v3 -u user2 -l authPriv -a MD5 -A "1234567890123456" -x DES -X "1234567890123456" 192.168.120.177 \
1.3.6.1.4.1.318.1.1.12.3.3.1.1.4.10 i 2 \
1.3.6.1.4.1.318.1.1.12.3.3.1.1.4.11 i 2 \
1.3.6.1.4.1.318.1.1.12.3.3.1.1.4.12 i 2 \
1.3.6.1.4.1.318.1.1.12.3.3.1.1.4.13 i 2 \
1.3.6.1.4.1.318.1.1.12.3.3.1.1.4.14 i 2 
Timeout: No Response from 192.168.120.177

I restarted the NMC, no change. It also has the updated 3.9.3 firmware from 2021.

Is this normal? I thought it could handle 10 or 128 OIDs in one command.

How many OIDs can an AP79xx PDU receive over SNMPv3?