@David-TP 

Thanks for the response. After about a dozen reboots, all the nodes ended up choosing the same channel and all switched to 160mhz. I am using an Android app called Wifiman to monitor each node.

When it happens again (because it has done this a couple of time now) - I will get a screen shot.

Thanks

  @David-TP 

Here is my basement Deco using 160 while the other 3 are 80. See attached image. 

  @David-TP 

This morning the x90s decided not to follow the xe75s to channel 149. Issue now is that roaming only works on decos belonging to same channel. 

EDIT: Rebooted all decos and now my x90s are on two different channels. So my entire mesh network's 5ghz band is using 3 different channels, two different channel widths over 4 nodes. Roaming is completely broken too. I can only roam between the XE75s which leaves deadspots all over my house now. 

EDIT2: So if I force the network back to use 160mhz, there is a 50-50 chance all the nodes will switch to same channel. If they do, it's fine until I am automatically switched back to 80mhz because the app claims there is radar interference. This happens about once every 3 days. It's only when it is forcing the network back to 80mhz that the x90 nodes decide to pick a random channel and width. And once this happens, all my portables devices like laptops and phones won't switch to the x90s anymore. Those nodes are adding nothing to the mesh experience when this happens.

  @David-TP 

Any thoughts on this? My Wifi switched to 80mhz again and now the x90s are doing their own thing again. The "workaround" for this is to constantly force everything back to 160 but clearly that is not a good solution since the app keeps switching it back to 80 almost daily.

  @David-TP 

Still nothing? Guess I am on my own with this problem? I may have to switch back to my Eeros so that roaming between nodes actually works as advertised.

Not a happy customer.

  @David-TP 

Thank you for the information, it is very helpful. I did spend a couple hours today swapping my main deco out to be the X90 instead. This time I took the opportunity to have a wired backhaul for one of the units to help boost performance. I noticed as soon as I got everything back up that the wired XE75 was on 80mhz while the other three remained on 160mhz. I have not seen them move to different channels yet.

Unfortunately because I am using the X90 as the main deco, I no longer have the option to force the network back to 160mhz as this must have been a feature only available when the XE75 was the main deco. The only way I could get the rogue unit to switch to 160 was to unplug the ethernet and let us use a wireless backhaul. However, once I reconnected the wire, it went back to 80. This almost feels like a new issue compared to the first problem I had with units using different channels at the same time.

I rebooted and the issue persists. Is it possible that the software isn't telling wired nodes to follow the main deco's channel width? The wireless one was fine.

What it seems to me is that when the main deco switches width, the wired one does not follow.