Airpods (2017) call problem with both airpods in

Firstly, i am a very technically minded person, having worked for large blue chip technology organisations for 13 years, i am very confident this isn't anything to do with a 'reset' or any other bits of 'noddy' troubleshooting.

I have the original Airpods and iPhone 7 PLUS.

Firstly, i have replaced both Airpods AND iPhone under warranty AND THE PROBLEM STILL EXISTS!

PROBLEM:

If i have both airpods in when i make a call, people cannot hear me.

If i make a call with just a single airpod in, the left for example, then after the call connects, after 5 seconds, i put the right one in, the call is fine with both airpods.

If i disconnect the call without removing the airpods, any subsequent call is fine.

Please see this article that also explains it:

https://www.digitaltrends.com/home-theater/common-airpods-problems-and-how-to-fix-them/

Call drops

Intermittent call drops have plagued the AirPods since they debuted back in 2017. Fortunately, there is a simple fix that often works: Try taking calls with only one AirPod in your ear, not both.

Given the very strange process where calling with only one in seems to work, and then subsequent calls work, this HAS TO BE A SOFTWARE/FIRMWARE issue, given i have replaced both airpods and 7Plus and working in software myself, i feel this is something Apple know about but cannot fix or they aren't aware of it.

Either way, it needs resolving the iPhone 7 PLUS is a supported apple device for Airpods, therefore, should work.

Has anyone else seen this?