Horrendous call quality in car Bluetooth

[Clarky1989]

I've just switched to EE and ported my old mobile number over. In the interim when I used number on the EE SIM, the call quality in my car via Bluetooth was excellent and consistent with how it was before. Now as soon as my number has been ported over, if I make a call in my car the audio sounds like a compressed low quality 144p YouTube video and is completely useless. The flip side is if someone calls me in the car the then audio is perfect and crisp like before. I've done repeated tests with different phones all in good signal areas. How can I rectify this as currently it is completely broken.

[bristolian]

Your mobile number has absolutely no bearing on the codecs used for voice calls. Do you have the same problem when you're not using your vehicle's Bluetooth system?

Does VoLTE/4G-calling show on your phone's screen when you are making a call via your Bluetooth system? I appreciate this is not something that should be tested while driving when all ancillary use should be secondary anyway - but should be able to test while stationary.

[Clarky1989]

Hi there, I'll give it a test today. I've tried other phones via Bluetooth on my car and the sound is fine which leads me to believe it's an issue either with EE or my phone.

There's no VoLTE/4g calling setting on my pixel under the internet settings on the SIM card which apparently should be there and using the *#*#4636#*#* test on the phone shows the voice network as lte. 

Again when someone calls me and I'm using Bluetooth in the car it works absolutely fine but not if I make the call so I'm assuming it's something on EE or my phone that's doing it.

[Clarky1989]

Another issue is that when I text someone it uses the new number that was attached to the SIM EE sent, even now after my old number has been ported. I've read I need to get a blank SIM and do another transfer? 

[bristolian]

EE's mobile network has no knowledge of what audio equipment is connected to your phone - the reason I queried the VoLTE-status is that the most likely explanation for poor audio quality is that the affected calls are being routed over 2G/3G rather than IMS-based 4G.

When did you complete your number port, and have you restarted your phone since this was done? Does the correct CLID present on outgoing calls? Can you receive texts on the correct ported-in number?

[Clarky1989]

Number was ported about a week ago. when I call someone the number comes up correctly and I can receive messages but when I send messages it comes up as the interim number from the SIM card. I've restarted my phone multiple times since. 

I may try a factory reset later and see if that helps 🤷‍♂️.

[bristolian]

EE C/S may need to check that the number port has fully completed.

[Clarky1989]

Factory reset seemed to fix the incorrect number coming up over text messages. Under the phone status check option *#*#4636#*#* should the voice network type show as VoLTE or 4G? Just shows LTE currently. Putting the sim in my previous phone, a OnePlus 7T and the VoLTE logo displays along the top task bar.