Some Smart Switches and other 2.4 GHz devices are not that "smart" and get a serious bellyache when you are trying to pair them with the Orbi network. Most of these 2.4 GHz devices will have an associated smartphone app and newer smartphones that read both 2.4 and 5 GHz wifi will generally default to the 5 Ghz signal. Apparently as a function of it's dynamic mesh networking operation Orbi does not have the option to select out a separately named discrete 2.4 Ghz signal for these less bright devices to latch onto. The 2.4 signal exists but the device is not smart enought to pick it out and and bootstrap with it.
In my case the solution was simply to use an old smartphone (5 year old 1st gen little Moto G) gathering dust that was 2.4 GHz only, attach it to the Orbi wifi and install the device pairing app onto that phone and use it for pairing the device. Because the phone is 2.4 GHz only the device had no trouble latching onto the Orbi wifi signal through that interface and found the Orbi 2.4 wifi signal and installed itself on the network. Not a particularly elegant solution but it worked for me and it might be worth trying if you have an old wifi/ bgn 2.4 GHz phone or tablet hanging around and some balky devices.
