An interesting situation happened, zabbix-server stopped working after log rotation. The last message was cannot open "/var/log/zabbix/zabbix_server.log": [13] Permission denied.
It is rotated by a syslog in which it sets the rights create 0664 zabbix zabbix. Zabbix-server version 4.0.7, has been working for a long time and this is the first time such a situation.
cat /etc/logrotate.d/zabbix-server
_/var/log/zabbix/zabbix_server.log

{ weekly rotate 12 compress delaycompress missingok notifempty create 0664 zabbix zabbix }

_