How to turn off Smart WiFi?

I wanted to make a post about this, as all the threads I was finding didn't have the answer. I'm not a tech person, so bear with me if I oversimplify how WiFi works My problem I wanted to turn off Smart WiFi, which was automatically turned on when I got my new router. What is Smart Wifi?: Smart WiFi automatically chooses, on a per device basis, whether to connect you to the 2.4 or 5GHZ variant of WiFi. Both networks meshes are under the same network name... however, on a "normal" router, you'd just have two separate WiFi's, one for each variant. However...Why Certain of my smart devices (smart bulbs, smart plugs) can only connect to the 2.4GHZ variant. This is a problem, because in my apartment my phone is almost always connected to the 5GHZ variant.