For my own education someone please correct this if its wrong. I'm no router expert but that's the way I understand it. The 2.4GHz band can provide higher range, but the 5GHz band. For that reason it might be more desirable to lock into the 2.4 band only. The WiFi technology mainly uses three radio frequency bands, 2.4GHz, 5GHz, and 60GHz to establish connections with various devices. But one thing is certain, the range of the 5 band is less than the 2.4 band. Note, I'm not totally comfortable about the part with both bands not transmitting simultaneously. Then go back and enable the 2.4ghz radio and save the settings again. If it is already enabled, change it to disabled then save the settings near the bottom of the page. If this us correct you need to disable band steering so that both the 2.4 and 5 bands transmit simultaneously and independently of each other. There at the top of that menu you will see the very first item is 2.4 ghz wifi interface disable or enable. So if you have a 2.4-only device, with band steering enabled, and the band switches to 5 the 2.4-only device looses its connection (or may lose connection). That means only devices capable of receiving both bands will work with band steering.

The router does not transmit on both bands simultaneously (more about that shortly because that might be wrong). With band steering enabled the wifi will switch transmitting between the 2.4 and 5 bands. It’s my understanding that both the 2.4 and 5 gig bands can run concurrently, and that my weather device will know to use the 2.4 band since it’s capable of running only on that band. As stated there is a enable/disable switch for each of the bands.

What is a 2.4 ghz network