I have just replaced my HUB 2 with a HUB 3, the previous has worked with my setup with no issues for years.
As soon as I set the HUB 3 to modem mode the power light turns RED and the connection intermittently drops out.
I have tried powering down and also the reset button on the rear, it is located on a cupboard and completely free of any obstacles and the unit is not getting hot, but the problem persists, is there possibly an issue with the HUB 3 itself?
In modem mode the Hub3 light shoulkd be Magenta - this looks red/pink or whatever shade yoiu choose to some eyes in some lights. If it goes white when you go back to Router mode - then its fine.
Is your issue that you have your own router and didn't use the sequence below to connect it first time? ______________________________
Disconnect all cables from your new router (or Mesh first unit) and unplug it. Put the VM Hub into modem mode (see VM website for “how to” details) and wait for the base light to turn magenta/purple (on a Hub3 - but not on a Hub4!). Once it’s in modem mode, the VM hub must then be powered off. Then, set up your own router/Mesh with the WAN port set to be in DHCP & Nat mode, it may be pre-set that way anyway. Make sure it’s fully initialised (leave 5 min) and then put in the WAN cable to the VM hub. Now power up the VM hub and you should get a connection. Use the recommended App to connect other Mesh units to the first one. This order only needs to be done the first time you connect the router to the VM hub.
-------------------- John --------------------
I do not work for VM. My services: HD TV on VIP (+ Sky Sports & Movies & BT sport), x3 V6 boxes (1 wired 2 WiFi,) SH2 in modem mode with Airport Extreme Router +2 Airport Express's. On VIVID200, Talk Anytime Phone, x2 Mobile SIM only iPhones.