After beta 4 update bsnl volte not support OnePlus 8
As you mentioned you are on beta,
report this bug here
beta is all about finding the bug and reporting it.
and try to post beta related issues in the official beta thread they read comments there, no need to create a separate thread on beta related issues.
Ask Me Anything! Talking with PUGB MOBILE streamers – Powerbang, Medalcore and Wynnsanity
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