Same problem here. Did anyone ever manage to fix this? I've been in touch with ASUS support - all they could suggest was a hard reset, which I did. This has done absolutely nothing to change the situation. I'm considering sending it back to Amazon. Can't work like this. Really disappointed for such a "high-end" device !!
Looking though the logs, the router is just stopping and restarting no error messages of any meaning that I can see.
Log Extract:
Jan 9 08:07:02 acsd: Adjusted channel spec: 0x1001 (1)
Jan 9 08:07:02 acsd: selected channel spec: 0x1001 (1)
Jan 9 08:07:02 acsd: acs_set_chspec: 0x1001 (1) for reason APCS_INIT
Jan 9 08:08:31 wlceventd: CAP,01:B0: wlceventd_proc_event(432): eth8: Auth D4:D2:52:CA:3C:7B, status: 0, reason: d11 RC reserved (0)
Jan 9 08:08:31 wlceventd: CAP,01:B0: wlceventd_proc_event(442): eth8: ReAssoc D4:D2:52:CA:3C:7B, status: 0, reason: d11 RC reserved (0)
Jan 9 08:08:35 dnsmasq-dhcp[1087]: Ignoring domain centre1.uk.boots.com for DHCP host name CENTLPC16R2MZ
Jan 9 08:23:07 wlceventd: CAP,01:B0: wlceventd_proc_event(432): eth6: Auth 88:87:17:DA:4E:BD, status: 0, reason: d11 RC reserved (0)
Jan 9 08:23:07 wlceventd: CAP,01:B0: wlceventd_proc_event(460): eth6: Assoc 88:87:17:DA:4E:BD, status: 0, reason: d11 RC reserved (0)
May 5 05:05:08 kernel: klogd started: BusyBox v1.24.1 (2019-09-04 19:48:43 CST)
May 5 05:05:08 kernel: Linux version 4.1.51 (gitserv_asus@asuswrt-build-server) (gcc version 5.5.0 (Buildroot 2017.11.1) ) #4 SMP PREEMPT Wed Sep 4 20:34:30 CST 2019
May 5 05:05:08 kernel: CPU: AArch64 Processor [420f1000] revision 0
May 5 05:05:08 kernel: Kernel command line: coherent_pool=4M cpuidle_sysfs_switch pci=pcie_bus_safe rootwait
May 5 05:05:08 kernel: Virtual kernel memory layout:
May 5 05:05:08 kernel: vmalloc : 0xffffff8000000000 - 0xffffffbdffff0000 ( 247 GB)
May 5 05:05:08 kernel: vmemmap : 0xffffffbe00000000 - 0xffffffbfc0000000 ( 7 GB maximum)
May 5 05:05:08 kernel: 0xffffffbe00000000 - 0xffffffbe00e00000 ( 14 MB actual)
May 5 05:05:08 kernel: fixed : 0xffffffbffabfd000 - 0xffffffbffac00000 ( 12 KB)
May 5 05:05:08 kernel: PCI I/O : 0xffffffbffae00000 - 0xffffffbffbe00000 ( 16 MB)
May 5 05:05:08 kernel: modules : 0xffffffbffc000000 - 0xffffffc000000000 ( 64 MB)
May 5 05:05:08 kernel: memory : 0xffffffc000000000 - 0xffffffc040000000 ( 1024 MB)