Airpods not connecting to iPhone 16e (connects to other phones)

Got new Airpods Gen 2 and an iPhone 16e that I've had for 3 months.

Getting "connection failed" when trying to connect either automatically or manually.

Tested the airpods with 3 other iPhones and they connected fine. It's just my iPhone 16e that won't connect.

I have:

Updated to latest iOS

Forgotten all other devices connected via Bluetooth

Also tried the below several times in different sequences.

Reset network settings

Restarted iPhone (volume up, down, hold power)

Turned Bluetooth off/restarted phone/turned Bluetooth back on.

Every time it does see the airpods and tries to connect before coming up with the same error.

I've checked the airpods firmware from a other phone and they are on 6F21 which seems to be the latest for Gen 2.

Any further ideas please? Anyone else had issues specifically with iPhone 16e and Airpods?

Thank you.