iPhone connects to Xfinity Mobile Wi-Fi instead of home Wi-Fi

Here are some suggestions on how to prioritise your Wi-Fi networks:

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1. Most preferred network

Known wireless networks are scored based on your actions. When you manually connect to a network, its score increases. When you manually disconnect from a network, its score decreases. The network with the highest score is the most preferred.

2. Private network

Private wireless networks are those set up in homes and offices, and they can include a Personal Hotspot. The most recently joined network has highest priority.

3. Public network

Public wireless networks are designed for general access in public places such as hotels, airports, and coffee shops, and they can include Passpoint (Hotspot 2.0) and EAP-SIM networks. Known public networks can also include managed networks set up by your wireless carrier and its partners.

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4. Configuration method

Private wireless networks configured using a device management service are preferred over manually joined networks.

5. Highest supported Wi-Fi standard

Highest to lowest priority:

• Wi-Fi 7 networks
• Wi-Fi 6E and Wi-Fi 6 networks
• Wi-Fi 5 networks
• and so on

6. Frequency band

Highest to lowest priority:

• 6 GHz
• 5 GHz
• 5 GHz (DFS)
• 2.4 GHz

7. Security

Highest to lowest priority:

• WPA Enterprise (any version)
• WPA Personal (any version)
• WEP (any version)
• An open (unsecured) wireless network that wasn't manually joined in the past 2 weeks isn't auto-joined, unless it was installed on the device as a managed network in the last 24 hours.

8. Signal strength

The wireless network with the strongest signal has highest priority. Learn about signal strength and RSSI.

After restarting an iPhone or iPad, Wi-Fi credentials become available only after you unlock the device. Your device can then automatically join a known wireless network.

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copied from: How Apple devices decide which known wireless networks to auto-join - Apple Support