iPhone XR iOS 13.3.1 no visual voicemail since update

[DevonMalteser]

My daughter has an iPhone XR and since the phone updated to iOS 13.3.1 she has lost visual voicemail. She travels to/from uni every week and apparently phone keeps telling her she has voicemail but when she calls it there are no messages?! Last night she had a voicemail from a random chap telling her to stop phoning him or leave a voicemail. (I’m wondering if that’s a phishing one) It’s driving her mad!
I have an iPhone 7 and visual voicemail is still working fine! Yes, we’re both on iOS 13.3.1. Just trying to figure out if anyone has come across this or found a solution please?
Thanks!

[MI5]

@DevonMalteser 

Have a look at help here https://www.o2.co.uk/help/phones-sims-and-devices?page=topic/voicemail/visual-voicemail/device/apple...

[DevonMalteser]

Thanks. I’ll get her to go through it. She knows how to use visual voicemail, it got removed with latest iOS update 🤷🏻‍♀️

[MI5]

Has she upgraded or changed tariff recently?
The iData bolt on may not be active.
She can also try sending the word "STATE" to 9011

[DevonMalteser]

No, neither 😔
Since iOS update kicked in.
We tried instructions but no luck 😞
I’ll text the ‘state’ - not tried that x
Thanks x

[MI5]

Check the data apn is still set to "idata.o2.co.uk" and the same for vvm too.

[DevonMalteser]

Yep, both set to that. Think we’ll be calling O2 tomorrow to troubleshoot x

[MI5]

Ask them to check that iData bolt on is still active.

[DevonMalteser]

Thank you x
Much appreciate your time and advice

[MI5]

Good luck and come back to let us know what happens.