Call fails after a few seconds

[csarant]

I am using an iphone XS

As of yesterday (6 July 2021) A few seconds after I make or receive a call, the other party stops hearing me, as if I am on mute.

I tried with a different SIM with the same results.

I tried WiFi calling and 3G and the issue disappears. 

Whilst on 4G, I disabled VoiceOverLTE (VoLTE) and the issue also disappears. This leads me to think it is VoiceOverLTE issue,

My work phone is an iphone 8 on Vodafone and it works fine with VoLTE enabled. I also used my SIM on my work phone and it works fine with VoLTE enabled.

Therefore, it seems that either Vodafone has an issue with VoLTE on iphone XS or (less likely) my phone has an issue with VoLTE. I also performed a couple of hard resets on the phone to no avail.

My post code is CM11 2DL

Any ideas?

[Evie]

Hey there @csarant - How odd 🤔 I've checked your postcode on our network systems and 4G is registered fine, there's good outdoor and indoor signal in your area and your local mast (No. 19073) is working as it should be.

Do you have any other issues over 4G? Data usage or sending iMessages?

Do you have the latest software update on your phone?

[csarant]

I agree, it is a weird issue.

The problem appeared since yesterday. I noticed in in the afternoon.

On the top floor of my house, where I faced the issue, I have full 4G signal both indoors and outdoors, thus it is not a signal quality issue.

I just did a speedtest on the data and the results are appalling: 1.17 Mbps upload and 0.12 Mbps download

Can it be a base station capacity issue?

[Mark]

Hey @csarant, We're not aware of any of our other customers struggling to use VoLTE service with an iPhone XS. I can see you've advised the issue still occurred when you popped another SIM into your handset, but experienced no issues with your SIM in another handset. This indicates the issue you're experiencing could be connected to the phone as this is one of the common factors in all your problematic connections. Does happen when you're out and about, or is it just when you're at home?

[csarant]

That's a great question. I have not tested it when I am out and about.

I will test it and I will post the results here.