iWatch Series 7 & iPhone 14 Pro Max issue

I don't exactly understand. Are you trying to use the same watch that was paired with your iPone 12 Pro Max with your new iPhone 14 Pro Max? If so, did you unpair the watch from the iPhone 12 Pro Max first? An Apple Watch can only be paired with one iPhone at a time. You should follow the steps in the 'If you don't have your old iPhone or you erased it' section of:

How to pair your Apple Watch with a new iPhone - Apple Support

Here are two ways to unpair your watch if you no longer have the paired iPhone:

• See the 'How to erase your Apple Watch if you don't have your iPhone' section of:

Unpair and erase your Apple Watch - Apple Support

• With a web browser, go to: https://www.iCloud.com and sign in with your Apple ID. Open Find My iPhone and select All Devices (at the top). Then click your Apple Watch, select 'Erase Apple Watch', and select Next until the device is erased. Finally click "X" next to remove your Apple Watch.