Connecting 2.4 GHZ devices to Orbi

Millions of devices are sold to connect to wi-fi, many for Alexa usage.  These require setup using the 2.4 ghz band.  The are configured via a phone or tablet that downloads the manufacturers app.  If the phone or table connects at 5 ghz the setup won't complete.  Android has eliminated the ability to designate the connection speed.  The community suggests lowering the 5 ghz to 25% and going as far away from the router as possible. I have tried that without success.  Also, this is a solution that assumes some technical ability.  I have had to disable the Orbi and use an old router with seperate 2.4 and 5 ghz bands to configure 3 new devices..  You need to come up with a way to simply configure devices.