Reconnecting Bluetooth items with the iPhone 12 Pro max

Make sure that your Bluetooth accessory and iOS or iPadOS device are close to each other. Turn your Bluetooth accessory off and back on again. Make sure that your Bluetooth accessory is on and fully charged or connected to power. If your accessory uses batteries, see if they need to be replaced.

If you can't connect a Bluetooth accessory to your iPhone ...

this seems to not be the answer, I can pull my iPhone 11 out and it connects fine but none of the 4 new iPhone 12's will attach or even see the Bluetooth device. is the iPhone 12 using a different Bluetooth tech?