How do I toggle from 5GHz to 2.4GHz on my iPhone 14 Pro Max?

Configure your Wi-Fi router to use separate wireless network names for the 2.4 GHz and 5 GHz bands.

Keep in mind that not all dual band routers have this capability though. If your Wi-Fi router does not this type of capability, it is broadcasting a dual band network that uses the same name for both the 2.4 GHz and 5 GHz signals. Your iPhone will connect to the strongest signal......which may not be the fastest signal.

Then, manually select either the 2.4 GHz or 5 GHz network from your iPhone.

You don’t.

As pointed out, your iPhone will automatically connect to whatever frequency it detects has the best quality.

If for whatever reason you want to select it, you will have to use your WiFi router to split each frequency into its own network.

From what I can tell, the Alien Amplifi is a router you would purchase if your ISP only supplies a modem (does not have a built-in router).

The ISP's modem should have its own password. The Alien router should be separate.

The only manual I could find makes it look like you have to do all configuration changes through an app on your smart phone.

However you can get at the settings, you're looking under the Wi-Fi settings for Band Steering, such as the example here for our Motorola, Xfinity compatible modem.

If it's enabled, then you use only one SSID name for both bands. Here, I disabled it so I could give each Wi-Fi band its own SSID name.

If you mean for a cellular connection, you can't control that. The phone will choose the fastest of whatever is available.

For Wi-Fi, you choose the 5G signal from your router.

Per Bob, most routers use a separate SSIDs for the two bands. If you only see one Wi-Fi signal to select, then it's likely using the same SSID for both signals.

Our Motorola, Xfinity compatible router came as a shared dual band. I separated them into single bands so I could choose a specific one where necessary. Such as, our Sony HD Blu-ray deck doesn't work with 5G, and wouldn't even show a shared SSID.

jlnowling wrote:

I have an app for my sewing machine that will only work on 2.4 GHz. I use to have a iPhone 10 and never had an issue until I got the 14 Pro Max.

I only have one SSID for my router. I also have a number of devices that only use 2.4 GHz. They all seem to manage just fine. It's possible the issues lies not with the app but with the device in question. Have you tried some basic troubleshooting? Unplug the router, wait a few minutes then plug it back in. Have you tried deleting the sewing machine app and re-installing it? Have you check with your sewing machine manufacturer to see if they have any troubleshooting information?