Multy U AC2100 problems, node restarts on high load and another node stopped working correctly

Oystein Hermansen
edited May 21 in Wireless
Multi U Wifi Mesh from Zyxel.  3 nodes, firmware V1.00(ABMY11)CO (latest version).

Main unit running in BRIDGE MODE.  Node 2 and 3 connected to main unit using wireless only.  
System was first installed in October 2020 with two SSIDs (one for 2.4 and one for 5 Ghz) and has been running without any problems since then.  But in December (week 51/52) I got problems.

Node 3 starting acting strange.  Used Wifi-scanner and found that it had stopped broadcasting the SSID for 5 Ghz.  Tried to restart all units.  Did not correct the problem.  Wifi scanner found all 3 three back-bone channels open (Main - Node 2, Main - Node 3, Node 2 to Node 3).  But Node 3 refused to broadcast SSID for 5 Ghz, only the SSID for 2.4 Ghz. 

Removed Node 3 using the app on my iPhone and powered it off.  Restarted the whole system (Main unit and Node 2).  A Wifi-scan shows the back-bone channel on 5 Ghz and 2 SSIDs available (2.4 and 5 Ghz) from each node (Main and Node 2).  System seems to work ok, but I have experienced an unplanned reboot of Node 2 two times.  My AppleTV and smart-TV is connected to Node 2 using Ethernet through a switch (historic reasons). Node 2 functions as both a wired-wireless gateway (which it supports and have done without problems for 2 months) and as a mesh unit broadcasting SSIDs for 2.4 and 5 Ghz.

There are currently between 15 and 20 active (from time to time) wifi clients using the SSIDs.

By using Wifi-scanner, I see that the Wifi network is not overcrowded and should provide no problems.

Problem as I see it:
1) Why did Node 3 stopped working like it should and not broadcasting and allowing connections over 5 Ghz?

2) If I sit approx 3 meter (in my living room) my laptop is connected to Node 2.   Starting a Speedtest from ( will force a reboot of Node 2 approx 30% (⅓) of the times.  I am connected to a 100 mbps Internet using fiber.  
If I do the same speedtests using the Speedtest app from my AppleTV connected to Node 2, it never reboots.  I get a 95/95 mbps from my AppleTV.  From my laptop (Apple Macbook Pro) I get the same results (95/95 mbps) if Node 2 doesn´t reboot.  Such reboots of Node 2 have also happend if there are many clients connected to Node 2 and they create much traffic (TCP/UDP traffic). 

Any advice?  

All Replies

  • Zyxel_Jerry
    Zyxel_Jerry Posts: 1,198  Zyxel Employee
    First Anniversary 10 Comments Friend Collector First Answer
    Dear Sir,

    We have received your feedback from Multy App, and we will contact you via email. 

    Best regards,