Zabbix server queue has increased significantly.

Steps to reproduce:

1. update zabbix server from 5.4 to 6.0.6 version
2. Check Zabbix server queue graphs before and after update

Result:
Zabbix queue graph shows significant growth
Expected:
no changes in zabbisx queue

On attached screenshots we can see situation before update (first) and after update (second) for "Zabbix queue" item with key "zabbix[queue]". 
No configuration change was performed
No errors in logs for zabbix server on database
Overall situation is the same exept for zabbix version changed. 

Has something changed in the way how zabbix queu ceck is performed?
How does that parameter affects zabbix performance? 
Should we do somthing about that queue, or momentum zabbix queue (<5 sec ) is OK?