ARRIS SURFboard mAX Tri-band Mesh

I am SO VERY MAD at myself for waiting until after the return window closed to install these!I purchased 2 of the W121 sets to replace my existing mesh wireless system. My existing system worked fine, but the company which made them had stopped providing security updates, so I decided to replace it. Since I had a mesh system with 1 base and 2 satellites and wanted at least the same number of mesh boxes. So, I bought 2 of the W121 sets (even though the tech support said it could only use the base and 2 satellites) because buying a second pair on sale was about the same price as a single unit.The hardware appears to work well, but they made an incredibly bad decision in forcing the use of an app to configure and setup the device. I trusted a big name like Arris to not completely mess things up, but holy cow is that app horrible. I see other people with the exact same issue as me (the app refuses to connect satellite units and is crazy slow in initial setup.)As of now, the base is working as a stand alone/single unit, but I can't access it with the app unless I do a factory reset (you have to use a paperclip or similar item and press and hold the reset button hidden in the tiny hole by the network port for a long time - they told me to do 30 seconds.) Once I do that, the app will let me completly start the install process over, but it refuses to add any additional units and just hangs eventually. Restarting the app takes it back to the initial install screen with no option to bypass it.ARRIS - IF YOU ARE GOING TO ONLY PROVIDE AN APP FOR SETUP, MAKE SURE THE APP WORKS!!! So very, Very, VERY angry with whoever made this decision at Arris.There was no documentation in the box (mine was completely new with all the shrinkwrap and the plastic peel-off intact, so its not like the issue was someone sneaking a used unit into my sale), just a 2D barcode for directing the owner to download their (horrible!!!) app.Update: Feb 17 2023. I have a couple of items to add.1) I used one of the "spare" units as a stand-alone device for my in-laws. Since it the app had been updated in the Google Play store, I had my wife install it on her phone and used that to set it up (my thought was that it would not have any trace of the issues I had with our home unit.) She had similar issues, but after a lot of playing around, I got it to work.2) I uninstalled the app on my phone and re-installed it, then tried to see if it would let me add a satelite. No luck!.So, really frustrating as the hardware works great, but the install/management app is so bad.P.S. I saw one person put out a rave review about how easy the app is to use. Unfortunetly, he is misunderstanding what people are complaining about. Its not that the app is hard to use (it appears to be VERY simple and has a lot of newbie friendly options.) The issue is it DOES NOT WORK for most people and there is no other option to setup and mange the hardware than with their broken app, so until/if they fix the app, its going to be a gamble on whether this is a nightmare or a win for you.If this thing works well for you, maybe list out what type of device you use to set it up??? I know my Android phones have not had luck, so maybe IOS users have better luck???