Why an iPhone 15 May Not Join the 6 GHz Network That a 15 Pro Uses

Check the exact iPhone model before changing the router. Apple's supported-device list includes iPhone 15 Pro and 15 Pro Max for 6 GHz-capable Wi-Fi but excludes iPhone 15 and 15 Plus. A model lacking that capability cannot gain it through a network reset. Use a supported band instead.

Identify the comparison

The claim “the same phone works on 6 GHz” is often a comparison between different models in one generation. Confirm the full names on both phones and the router's actual bands. A network advertised as Wi-Fi 6 is not necessarily a 6 GHz network; the generation label and frequency band are separate details.

Apple's Wi-Fi guidance describes hardware requirements and a single network name across bands. Its model-identification guide helps distinguish similarly named devices. Use those documents rather than assuming that Pro is only a camera or storage difference.

Resolve the connection choice

Verify whether the affected phone is iPhone 15, 15 Plus, 15 Pro or 15 Pro Max in About. If the device is second-hand or relabeled, compare the A-number with Apple's model information before drawing a capability conclusion.
Ask the router administrator whether a 2.4 GHz or 5 GHz service is available. If you do not administer the router, do not factory-reset it to troubleshoot a phone feature. A hotel or workplace may offer a compatible network separately.
Join an appropriate supported network and test ordinary access. If it works, the missing 6 GHz path does not establish a Wi-Fi hardware failure. Check actual performance for your task rather than treating the highest band label as mandatory.
On a supported Pro model that still has trouble, follow Apple's network guidance and inspect router configuration with the administrator. Do not transfer instructions for changing Wi-Fi 6E mode to a phone that lacks that option.
If the phone cannot use any supported network, switch to the existing iPhone Wi-Fi workflow. That is a broader failure than the specific hardware distinction covered here.

Interpret the results

An iPhone 15 connecting successfully on a supported band while a 15 Pro uses 6 GHz is consistent with the documented model difference. Both phones failing on the same compatible network points toward a shared network issue. A supported Pro failing only on one router requires the router/device configuration comparison rather than immediate replacement.

Regional and later-model limits

6 GHz use is also subject to regional availability and network configuration. This guide compares four specific iPhone 15 models; it does not promise the same feature matrix for every later generation. Check Apple's current supported-device list before buying another phone for this feature.

Warnings

Do not install firmware, router certificates or a “6 GHz unlock” app from an unknown source. Do not weaken network security merely to force connection. If the available network is managed by someone else, ask for a compatible authorized option rather than trying to bypass its access rules.