Hi,

I noticed my internet connection dropped frequently after upgrade my router to M9 Plus.

When the situation happened, I firstly noticed no internet connection on my device, then the light on M9 Plus turned solid red, after about 1 minute the light turned back to green, and the connection restored afterwards. During disconnection the lights on my modem seems normal. It happens frequently like 5-6 times per day and was never happened before I using previous router.

I have 3 M9 Plus. The main one connects to the modem provided by my ISP provider. 2 other machines connect to main unit wirelessly.

I called TP-Link service and did the following: turn off 5G, set DNS to 8.8.8.8, and change connection type from Dynamic IP to PPPoE but it does not help.

The system log around disconnection is copied below, hope it helps. This one is cropped from "DEBUG" page:

  daemon.info pppd[26845]: No response to 5 echo-requests
  daemon.notice pppd[26845]: Serial link appears to be disconnected.
  daemon.notice netifd: internet (26845): No response to 5 echo-requests
  daemon.notice netifd: internet (26845): Serial link appears to be disconnected.
  daemon.notice netifd: internet (26845): Command failed: Not found
  daemon.notice netifd: internet (26845): Command failed: Not found
  daemon.info pppd[26845]: Connect time 22.4 minutes.
  daemon.info pppd[26845]: Sent 10818308 bytes, received 452080882 bytes.
  daemon.notice netifd: internet (26845): Connect time 22.4 minutes.
  daemon.notice netifd: internet (26845): Sent 10818308 bytes, received 452080882 bytes.
  daemon.notice netifd: Network device 'pppoe-internet' link is down
  daemon.err miniupnpd[28291]: ioctl(s, SIOCGIFADDR, ...): Cannot assign requested address
  daemon.err miniupnpd[28291]: Failed to get IP for interface pppoe-internet
  daemon.warn miniupnpd[28291]: SendNATPMPPublicAddressChangeNotification: cannot get public IP address, stopping
  daemon.notice netifd: internet (26845): Command failed: Not found
  daemon.notice netifd: internet (26845): Command failed: Not found
  daemon.notice pppd[26845]: Connection terminated.
  daemon.notice netifd: internet (26845): Connection terminated.
  user.debug netifd: ubus call network.interface notify_proto { "action": 0, "ifname": "pppoe-internet", "link-up": false, "keep": false, "interface": "internet" }
  daemon.info pppd[26845]: Sent PADT
  daemon.notice netifd: internet (26845): Command failed: Not found
  daemon.info pppd[26845]: got_sigchld
  daemon.notice pppd[26845]: Modem hangup
  daemon.notice netifd: internet (26845): got_sigchld
  daemon.notice netifd: internet (26845): Modem hangup
  daemon.notice netifd: Interface 'internet' has lost the connection
  user.notice ppp: pppoe-internet link down
  daemon.info pppd[26845]: got_sigchld
  daemon.info pppd[26845]: Exit.
  daemon.notice netifd: internet (26845): got_sigchld
  daemon.notice netifd: internet (26845): write buf error
  daemon.notice netifd: internet (26845): : No such file or directory
  user.notice pppoe: teardown internet br-wan
  user.notice ppp: teardown internet
  user.debug netifd: ubus call network.interface notify_proto { "action": 2, "signal": 15, "interface": "internet" }
  daemon.notice netifd: Interface 'internet' is now down
  daemon.notice netifd: Interface 'internet' is setting up now

Many thanks for any advice and help!