Do you have SSH access to the router enabled? 
LAN only or 
LAN & WAN?
It would helpful if you could SSH into the router and post the output from these commands:
	
	
		 
SSH Only Lan.
removed some sensitive data from the output here
ls -altr /tmp/:
drwxr-xr-x    4 'username'  root            80 Dec 31  1969 var
drwxr-xr-x    2 'username'  root            40 Dec 31  1969 share
-rw-r--r--    1 'username'  root             0 Dec 31  1969 settings
drwxr-xr-x    3 'username'  root            60 Dec 31  1969 notify
drwxr-xr-x    2 'username'  root            40 Dec 31  1969 inadyn.cache
drwxr-xr-x    3 'username'  root            60 Dec 31  1969 home
-rw-r--r--    1 'username'  root             9 Dec 31  1969 misc.json
drwxr-xr-x    3 'username'  root            60 Dec 31  1969 confmtd
-rw-rw-rw-    1 'username'  root           506 May  5  2018 wl1_hapd.conf
-rw-rw-rw-    1 'username'  root          1264 May  5  2018 wl0_hapd.conf
drwxrwxrwx    2 'username'  root            40 May  5  2018 netool
-r-sr-x---    1 'username'  root             0 May  5  2018 ebtables.lock
drwxrwxrwx    2 'username'  root           100 May  5  2018 dm
-rw-rw-rw-    1 'username'  root             0 May  5  2018 awsiot_log
drwxrwxrwx    3 'username'  root            80 May  5  2018 avahi
drwxrwxrwx    2 'username'  root            80 May  5  2018 asdfile
-rw-rw-rw-    1 'username'  root             0 May  5  2018 asd.init
-rw-rw-rw-    1 'username'  root            64 May  5  2018 lld2d.conf
lrwxrwxrwx    1 'username'  root             8 May  5  2018 ipsec_updown -> /sbin/rc
drwxrwxrwx    2 'username'  root            40 May  5  2018 asusfbsvcs
-rw-rw-rw-    1 'username'  root           355 May  5  2018 run_lldpd.sh
-rw-rw-rw-    1 'username'  root             0 May  5  2018 mastiff_log
-rw-rw-rw-    1 'username'  root             5 May  5  2018 mastiff.pid
-rw-rw-rw-    1 'username'  root            64 May  5  2018 lldpd_bind_ifnames
-rw-rw-rw-    1 'username'  root          4286 May  5  2018 lighttpd.conf
drwxr-xr-x    2 'username'  root            40 May  5  2018 cfg_mnt
lrwxrwxrwx    1 'username'  root             8 May  5  2018 zcip -> /sbin/rc
lrwxrwxrwx    1 'username'  root             8 May  5  2018 wpa_cli -> /sbin/rc
lrwxrwxrwx    1 'username'  root             8 May  5  2018 udhcpc_wan -> /sbin/rc
lrwxrwxrwx    1 'username'  root             8 May  5  2018 dhcp6c -> /sbin/rc
-rw-r--r--    1 'username'  root            56 May  5  2018 relist.json
-rw-rw-rw-    1 'username'  root            92 May  5  2018 obvsie
-rw-rw-rw-    1 'username'  root             1 May  5  2018 obstatus
-rw-rw-rw-    1 'username'  root            92 May  5  2018 guest_vsie
drwxrwxrwx    2 'username'  root            60 May  5  2018 asusdebuglog
-rw-r--r--    1 'username'  root            72 May  5  2018 *****.cap
-rw-r--r--    1 'username'  root            31 May  5  2018 ****.bi
-rw-rw-rw-    1 'username'  root           411 May  5  2018 filter_ipv6.default
-rw-rw-rw-    1 'username'  root           888 May  5  2018 filter.default
-rw-rw-rw-    1 'username'  root            18 May  5  2018 rast_stc_idx1
-rw-rw-rw-    1 'username'  root            18 May  5  2018 rast_stc_idx0
-rw-rw-rw-    1 'username'  root           176 May  5  2018 chanspec_avbl.txt
-rw-r--r--    1 'username'  root           185 May  5  2018 aplist.json
-rw-r--r--    1 'username'  root            31 May  5  2018 *****.bi
-rw-r--r--    1 'username'  root           185 May  5  2018 ****.cap
drwxrwxrwx    5 'username'  root           240 May  5  2018 lighttpd
-rw-r--r--    1 'username'  root           368 May  5  2018 *****.json
-rw-rw-rw-    1 'username'  root          2445 May  5  2018 diag_port_status.json
-rw-rw-rw-    1 'username'  root            10 May  5  2018 udhcpc0.expires
-rw-rw-rw-    1 'username'  root          1094 May  5  2018 nat_rules__eth0
-rw-r--r--    1 'username'  root            43 May  5  2018 maclist.json
drwxrwxrwx    2 'username'  root           600 May  5  2018 err_rules
-rw-------    1 'username'  root           285 May  5  2018 wan0_ppp.env
drwxrwxrwx    3 'username'  root           320 May  5  2018 ppp
drwxrwxrwx   20 'username'  root          1776 Apr 26 16:29 ..
-rw-rw-rw-    1 'username'  root           469 Jul 31 22:34 release_note0.txt
-rw-r--r--    1 'username'  root            43 Oct 21 09:31 resolv.dnsmasq
-rw-r--r--    1 'username'  root            51 Oct 21 09:31 resolv.conf
-rwxrwxrwx    1 'username'  root          1204 Oct 21 09:31 ipsec_iptables_rules
-rw-rw-rw-    1 'username'  root             0 Oct 21 09:31 aaews_log
-rw-rw-rw-    1 'username'  root             5 Oct 21 09:31 aaews.pid
drwxrwxrwx    2 'username'  root           180 Oct 21 09:31 nc
-rwx------    1 'username'  root             0 Oct 21 09:31 .bwdpi.rule.lck
-rwx------    1 'username'  root             0 Oct 21 09:31 .bwdpi.appdb.lck
-rw-rw-rw-    1 'username'  root        262188 Oct 21 09:31 syslog.log-1
-rw-rw-rw-    1 'username'  root          1438 Oct 21 09:31 redirect_rules
-rw-------    1 'username'  root          1264 Oct 21 09:31 nat_rules_ppp0_eth0
lrwxrwxrwx    1 'username'  root            24 Oct 21 09:31 nat_rules -> /tmp/nat_rules_ppp0_eth0
-rw-rw-rw-    1 'username'  root          6305 Oct 21 09:31 filter_rules
-rw-rw-rw-    1 'username'  root            19 Oct 21 09:32 hw_auth_clm
-rw-------    1 'username'  root           205 Oct 21 09:33 sig_upgrade.log
-rw-rw-rw-    1 'username'  root         65770 Oct 21 09:38 ce0.log.bak
-rw-r--r--    1 'username'  root           263 Oct 21 09:40 wchannel.json
-rw-r--r--    1 'username'  root           398 Oct 21 09:40 chanspec_private.json
-rw-r--r--    1 'username'  root           232 Oct 21 09:40 chanspec_avbl.json
-rw-r--r--    1 'username'  root           854 Oct 21 09:40 chanspec_all.json
drw-------    3 'username'  root           480 Oct 21 10:06 bwdpi
drwxrwxrwx    3 'username'  root            60 Oct 21 10:09 mnt
-rw-rw-rw-    1 'username'  root         15758 Oct 21 10:29 ce0.log
-rw-rw-rw-    1 'username'  root           200 Oct 21 10:30 webs_upgrade.log
drwxr-xr-x   12 'username'  root          1760 Oct 21 10:48 etc
-rw-rw-rw-    1 'username'  root             0 Oct 21 10:49 syscmd.log
-rw-rw-rw-    1 'username'  root          3987 Oct 21 10:49 apscan_info.txt
-rw-r--r--    1 'username'  root           846 Oct 21 10:49 allwclientlist.json
-rw-rw-rw-    1 'username'  root          8841 Oct 21 10:50 syslog.log
-rw-rw-rw-    1 'username'  root          3510 Oct 21 10:51 usb.log
drw-rw-rw-    2 'username'  root           280 Oct 21 10:51 .diag
-rw-rw-rw-    1 'username'  root          3496 Oct 21 10:51 dev
drwxrwxrwx   24 'username'  root          1940 Oct 21 10:51 .
-rw-------    1 'username'  root           791 Oct 21 10:51 MON_CHECK_
-rw-r--r--    1 'username'  root          3144 Oct 21 10:52 clientlist.json
-rw-r--r--    1 'username'  root            59 Oct 21 10:52 ********.port
-rw-r--r--    1 'username'  root          1451 Oct 21 10:52 wiredclientlist.json
-rw-r--r--    1 'username'  root           721 Oct 21 10:52 current_wired_client_list.json
drwx------    2 'username'  root            60 Oct 21 10:52 db
-rw-rw-rw-    1 'username'  root             0 Oct 21 10:52 watchdog_heartbeat
-rw-r--r--    1 'username'  root         45045 Oct 21 10:52 nmp_cache.js