[RT-AC88u] understanding the system log

Firmware Version:3.0.0.4.384_81116

Hi,
I got some problems with my two RT-AC88u an try to solve the issues mentioned in the systemlog
I got a scheduled reboot a 04:00.

Systemlog:
Mar 13 04:00:35 kernel: EMF_ERROR: Interface br0 doesn't exist
May 5 07:05:07 kernel: klogd started: BusyBox v1.25.1 (2019-09-19 10:55:51 CST)
----140 lines--
May 5 07:05:31 ntp: start NTP update
Mar 13 04:02:57 rc_service: ntp 790:notify_rc restart_diskmon

is it normal that every reboot there is a entry from...

[RT-AC88u] understanding the system log