Remote logging don’t work if src-address is not set (in default configuration). src-address is missing from actions list:
[admin@MikroTik] /system logging action> print detail
Flags: * - default
0 * name="memory" target=memory memory-lines=100 memory-stop-on-full=no
1 * name="disk" target=disk disk-file-name="log" disk-lines-per-file=100 disk-file-count=2 disk-stop-on-full=no
2 * name="echo" target=echo remember=yes
3 * name="remote" target=remote remote=1.2.3.4 remote-port=514 bsd-syslog=no syslog-facility=daemon
syslog-severity=auto
In Winbox there is (default) src-address=‘::’ (but router has no ipv6 package installed).
After setting src-address to 0.0.0.0 (and reboot if set from console) remote syslog starts working.
Sometimes this happens after upgrade from 4.x.
Maybe this can help someone.
Tested on x86 and mipsle, 5.4 and 5.5.