I did all of the above and I still only get found out of one
AirPod pro, getting sound out of one and I just bought them,
Question marked as
If you have already tried the steps in the Apple article that you referenced, then you will need to contact Apple directly for resolution. If you purchased them within the last 14 days, you can just return them for either a replacement or a refund.
If past then, then use this link: AirPods Service and Repair - Apple Support