SNMP OID and VLAN

Hello. I have a question about SNMP values.

I’ve got Mikrotik RB751 and I got SNMP values on ether2 port such as ifInOctets.2 or ifOutOctets.21 (speed per second)
I made a graph on Zabbix with this values.

Now I’ve got VLAN interface on physical ether2 (ifInOctets.2) interface.
VLAN SNMP values is called ifInOctets.30 and ifOutOctets.30.

So now I need to separate VLAN and ether1 traffic speed values.
I’ve made calculated item - last(“ifInOctets1”)-last(“ifInOctets30”)
and I got incorrect values in petabytes/s and exabytes/s

Then I read SNMP values of ifInOctets.1 and ifInOctets.30 by MIB Browser.

Here is it
ifInOctets.2 = 97590243
ifInOctets30 = 554438260

Name/OID: ifOutOctets.2; Value (Counter32): 1175292255
Name/OID: ifOutOctets.30; Value (Counter32): 892442707

How does it possible?
I thought that ifInOctests30 should be less number than ifInOctets.2, because it’s VLAN “inside” ether2 (ifInOctets.2)

Thanks!

Use

iso.org.dod.internet.mgmt.mib-2.ifMIB.ifMIBObjects.ifXTable.ifXEntry.ifHCInOctets.2
iso.org.dod.internet.mgmt.mib-2.ifMIB.ifMIBObjects.ifXTable.ifXEntry.ifHCOutOctets.2

(Counter64)

instead.