P1622178990937 , via OnePlus 8 , Oct 18, 2021 : Hey OnePlus, I am in Malaysia and have been using my oneplus 8 since it is in oos10 and the volte works normally. But once i update it to oos11, the volte is unusable and the volte and vowifi setting options are missing. Until now (oos 188.8.131.52IN21AA), the issues still presists. I won't be believe it is a issue with the service provider because before oos11 it works flawlessly. Please take note and address this issue immediately in the next OTA.