Asus RT N66u disconnessioni

[pilotz]

Salve a tutti,
Ho questo router da almeno due anni e solamente nell'ultima settiman mi trovo con un problema:
In sostanza quando provo ad accedere al wifi di casa sia con un oneplus che con un iphone6 (2.4 ghz) cade la connessione adsl:

Ho provato di ogni, cambiato cavi, resettato router, messo ultimo firmware uffciale ma il rpoblema rimane.
Nella rete ho 5 telecamere wifi, ipad (che non da problemi), server, pc fisso da gaming etc. Ho notato che finche i due cellulari non si connettono al wifi tutto è a posto.

Jan 1 01:01:54 pppd[419]: Connected to 00:90:1a:a4:33:9f via interface eth0
Jan 1 01:01:54 pppd[419]: Connect: ppp0 <--> eth0
Jan 1 01:01:54 pppd[419]: PAP authentication failed
Jan 1 01:01:54 pppd[419]: Connection terminated.
Jan 1 01:02:05 pppd[419]: Connected to 00:90:1a:a4:33:9f via interface eth0
Jan 1 01:02:05 pppd[419]: Connect: ppp0 <--> eth0
Jan 1 01:02:05 pppd[419]: PAP authentication succeeded
Jan 1 01:02:05 pppd[419]: peer from calling number 00:90:1A:A4:33:9F authorized
Jan 1 01:02:05 pppd[419]: local IP address 79.23.41.89
Jan 1 01:02:05 pppd[419]: remote IP address 192.168.100.1
Jan 1 01:02:05 pppd[419]: primary DNS address 85.37.17.10
Jan 1 01:02:05 pppd[419]: secondary DNS address 85.38.28.86
Jan 1 01:02:06 start_nat_rules: apply the nat_rules(/tmp/nat_rules_ppp0_eth0)!
Jan 1 01:02:06 kernel: nf_conntrack_rtsp v0.6.21 loading
Jan 1 01:02:06 kernel: nf_nat_rtsp v0.6.21 loading
Jan 1 01:02:06 wan: finish adding multi routes
Jan 1 01:02:06 rc_service: ip-up 535:notify_rc stop_upnp
Jan 1 01:02:06 miniupnpd[405]: received signal 15, good-bye
Jan 1 01:02:06 rc_service: ip-up 535:notify_rc start_upnp
Jan 1 01:02:06 miniupnpd[584]: HTTP listening on port 39375
Jan 1 01:02:06 miniupnpd[584]: Listening for NAT-PMP traffic on port 5351
Jan 1 01:02:06 ddns update: ez-ipupdate: starting...
Jan 1 01:02:09 WAN Connection: WAN was restored.
Jan 1 01:02:17 ddns update: connected to dynupdate.no-ip.com (8.23.224.120) on port 80.
Jan 1 01:02:19 ddns update: request successful
Jan 1 01:02:19 ddns update: asusddns_update: 0
Jan 1 01:02:19 ddns: ddns update ok
Jan 1 01:02:20 ntp: start NTP update
Sep 7 13:11:32 rc_service: ntp 589:notify_rc restart_upnp
Sep 7 13:11:32 miniupnpd[584]: received signal 15, good-bye
Sep 7 13:11:32 miniupnpd[597]: HTTP listening on port 47862
Sep 7 13:11:32 miniupnpd[597]: Listening for NAT-PMP traffic on port 5351
Sep 7 13:11:32 rc_service: ntp 589:notify_rc restart_diskmon