Sony Z5 echo during calls to some iPhones

[Freegle]

During a call the recipient is experiencing an echo which goes away if I hit speaker phone.

Any idea what is causing that? 

I can consistently resolve the echo by going on speaker phone or wearing a headset

Note not everycall I make has an echo.

I seem to consistently get complaints when the recipient is using an iphone 

But when I call someone who has an iPhone SE I don't have any echo issues.

I wish I knew what is was so I can fix it.

Any ideas?

I'm on SW Build number 32.2.A.0.305

Thanks

[MarlonUk1]

can you try this while you are on safe mode?

[Freegle]

I'll give it a try and keep you posted

[Freegle]

It still happens in safe mode

[MarlonUk1]

@Freeegle: hmm, this might be a network issue too, can you try to use another sim?

or how about try to perfrorm software repair using Xperia Companion?

[Freegle]

I've changed the SIM and no joy, same problem. This time I was calling a Samsung phone. Which means it is not related to calling iPhones as I thought.....just intermittent.

I hate intermittent problems they are harder to figure out....

I guess I will be  spending Christmas doing a software repair