On this page
16 Issues with SELinux
Socket-based inter-process communication has been added since Zabbix
3.4. On systems where SELinux is enabled it may be required to add
SELinux rules to allow Zabbix create/use UNIX domain sockets in the
SocketDir directory. Currently socket files are used by server
(alerter, preprocessing, IPMI) and proxy (IPMI). Socket files are
persistent, meaning are present while the process is running.