After upgrading Zabbix from 3.4.5 to 4.0.7, frequent triggering of the "Zabbix housekeeper processes more than 90% busy" trigger occurred. In some cases, the trigger hangs 48 minutes.
In version 3.4.5 this problem was not observed.
Uses postgres version 9.6 database.
No changes were made to the configuration of the zabbix server and postgres after the update.