Giving separate SSDIs to the 2.4GHz and 5GHz

I have some speakers that won't hook up to the wifi because they have issues connecting to the correct wifi band which is the 2.4GHz  because the SSDI is the exact same for both the 2.6GHz and 5GHz. I get in the perfect world your device should just connect to the correct band and the smart router is supposed to elevate this issue but in practice it's not working with some devices. I have tried to use the MEO smart wifi app to give each band their own SSDI but it doesn't allow you to same with trying adjust it using th FiberGateway site. How do I go about adjusting this myself or is it just not possible?