Weird high-pitched noises during calls, only when I call one person (iPhone SE 2022)

[Jugg]

Hi everyone,
I’m having a strange audio issue with my iPhone SE 2022.

Whenever I call one specific person (who has a Xiaomi Redmi Note 8), I hear random annoying high-pitched short noises / whistle sounds during the call — the sound typically starts if there is a sudden background noise around me (e.g. I turn on the water tap) and lasts just for a very short time (less than a second) but it's terribly annoying. Sometimes it starts even if the environment is apparantly quite.

Here’s what I’ve noticed:

• The noises appear only on my side (the other person hears me perfectly).
• If I mute my microphone, the problem disappear.
• It happens with and without earphones, with speakers, with apple CarPlay
• It doesn’t happen with other contacts.

So it seems to me the iPhone’s noise cancellation is over-reacting to environmental sounds and somehow feeding that distortion into my own earpiece, but I don't understand why it is happening only when I call this person.

I haven't found a setting to disable noise cancellation.

Has anyone else experienced this?

Is there any way to permanently the aggressive noise cancellation for calls?

Thanks in advance for any ideas !