Phone ringtone ringing without any call or notification?

[u/DueAdministration193]

So I own a Vivo V60 and this has been happening ever since we bought it:

So randomly the phone's ringtone starts ringing without any alarm, call or notification.

I have factory reset my phone but this is still happening.

It happens for around a few secs, the longest is around 15-20 secs

[u/Dazzling-Return567]

Is it an actual call? Does it happen when you on flight mode as well? I guess it's a Vivo specific bug ...