CM1000 modem / R8000 router - Smart Connect question

I replaced my Motorola modem/router with CM1000 & R8000 after I started having issues with my iphone & ipad showing connected, even though they weren't. I also had problems with unexplained runaway data usage. Smart connect was set up initially without issue. Over time, I started adding devices, and began having issues with some devices. Two devices were connecting to 2.4G & one device was probably trying to connect to 5G. I split the turned off Smart connect, and was able to resolve all of the issues I was having.

There doesn't seem to be a way for me to use Smart connect to split the 5G and 2.4G bands. I wanted to ask if there is any way to turn Smart connect back on and force those 3 devices to a specific band. I wanted to ask before going through the effort of switching the essid / password for all of my devices. I recall trying to reserve ip addresses for specific macs back when I was researching prior to turning off Smart connect, and wasn't having much luck. If I recall correctly, none of those 3 devices could be set up with a static ip. Thank you in advance for any guidance...