some snmp oid timeout

Good morning,

I’m trying to use zabbix with mikrotik to monitor some remote rb via snmp

zabbix is ​​installed on a remote vps and I try to connect to the customers’ rb through public ip (customers have wisp connection with cambium force 180/200 antennas which also act as nat) through portmapping of port 161 (10161 public and 161 private on ip of the rb)

I find myself this problem:

some oids do not respond (they time out both via zabbix and snmpwalk)
if I try to connect through a vpn instead they work correctly)

it looks like it’s 64bit oid, while 32bit works but I’m not sure

for example:

Received Octets:
1.3.6.1.2.1.31.1.1.1.6 (ifHCInOctets, 64-bit version) times out
1.3.6.1.2.1.2.2.1.10 (ifInOctets, 32-bit version) works

Transmitted Octets:
1.3.6.1.2.1.31.1.1.1.10 (ifHCOutOctets, 64-bit version) times out
1.3.6.1.2.1.2.2.1.16 (ifOutOctets, 32-bit version) works

in your opinion, what could cause the problem?

good day everyone