Zabbix poller process stops getting items from queue if next item has differences from previous ones.

For example. We have the following queue:
interfaceid, port, type, snmp_community, ....
1, 161, 1, public, ...
1, 161, 1, public, ...
1, 161, 1, public, ...
2, 161, 1, public, ...
1, 161, 1, public, ...
1, 161, 1, public, ...
1, 161, 1, public, ...
1, 161, 1, public, ...

1st poller - gets first 3 items.
2nd poller - gets 4th item
3rd poller - gets latest 4 items