Hello @Chip_Oidos
Thank you for your feedback
May I know the model of router, the firmware version of router, and can I have a photo of the Wi-Fi settings on the main router?
- Remove the router Wi-Fi profile on iPhone and reconnect to Router WiFi, could iPhone connect to Router SSID ?
How to remove existing wireless network profile on Android&iPhone
Then connect to Extender's Wi-Fi using the same router Wi-Fi password (RE uses the same wifi password as main router after being setup successfully)
- To isolate the issue, use an SSID for RE which is different from router's SSID
How to change wireless settings of TP-Link range extender on Tether APP
- If router uses WPA2/WPA3 mixed, try to change to WPA2-PSK AES and see if that helps
- Try to reset iPhone network settings with Apple support
If still the same, may I know IOS version of your iphone12 Pro? iPhone failed connect to 2.4Ghz or 5Ghz band of extended wifi? Could iPhone connect to the main router's SSID when you manually put in the WiFi password? Thank you