I need to pair devices like wireless doorbell and smart plugs. I need to temporarily disconnect 5g. The devices can only connect to 2.4gh. How can I do this?

Router keeps going on and off

NOTE: The dropdown model list does not list Archer A7, had to select the A10 to post this. I've tried two newly purchased AC1750s in the last 2 days. The first one kept dropping the primary connection

I have some products that can only connect to 2.4GHz networks. I have a dual band router. How do I make sure they are connecting to the proper 2.4 GHz network and not the 5GHz network?

"Spectrum upgraded to 200Mbs my Archer C50 gives slower hardwired speed than before upgrade." I connect directly to Spectrum's modem and Speedtest cranks at 240Mbs up / 12Mbs down, Through direct port

Every now and then the Router will shut down. Is there something I need to do to fix it?