Have you tried setting a voicemail pin to access emails from a different phone, just to see if that works?
Also, does it work in some countries and not others, if so, which ones?
I have no affiliation whatsoever with O2 or any subsidiary companies. Comments posted are entirely of my own opinion.
This is not Customer Service so we are unable to help with account specific issues.Currently using:
Pixel 7a (O2 & Lyca), One Plus 6 (Sfr), iPhone 12 Pro Max (Vodafone)