Delay between speaking and other person hearing on my iPhone 16 Pro Max

When I speak to others on the phone, after a few minutes the call starts to lag (if that’s the right word). I speak bjt there can be a delay of a few seconds before the other person hears me. It happens no matter who I’m speaking to.

I first noticed the issue on my iPhone X. I then got an iPhone 11 Pro, upgraded to 13 pro and then another upgrade to 16 pro max.

Every time I upgraded my device I used the function where you put both the old and new phones close together to transfer all data and setting to the new device.

I have had numerous conversations with Apple who have talked me through various settings. I’ve had numerous conversations with my network provider who have done the same, changed the SIM card and switched me to an eSIM but the problems still persists.

My partner and 2 children all have iPhones and use the same network provider as me and do not have this issue.

Im hoping there might be someone else whose noticed this issue and can advise on a fix.

thank you

[Re-Titled by Moderator]

Original Title: Delay between speaking and other person hearing.