I have the Verizon branded Oneplus 8 5UW. A while ago I noticed I was no longer receiving voicemail notifications. Probably happened after an update. Searching this issue I found others who had the same issue, And, like these others, after doing things like clearing cache and data for the phone app where visual voicemail is found and then rebooting, it will no longer activate with Verizon. I called and got passed from tier 1, through tier 2 and on to tier 3 support levels. Each one tried to resync/reset/reprovision voicemail on my account and had me clear cache and data and reboot and still visual voicemail will not activate. Just wondering if others had this issue and were able to fix it.
I did find a workaround. I set up a google voice account and used conditional call forwarding to forward declined and unanswered call there. GV voicemail works like a charm.