Loud ringtone randomly playing when phone on silent, but not tied to any notification

This has been happening to me too, same exact phone as you. I’m currently downloading 16.4.1 so we’ll see if it does anything but doubt it since this is the only thread I’ve found that mentions the same issue. Mine is basically random, maybe once a week where all notifications and lock tones are at max volume even though I put the volume and ringtone levels at the lowest. On silent, it’s fine and it’ll be silent. Usually once I soft reset or mess with alarm settings it’ll figure itself out but it’s starting to get annoying at this point.

This may be an insane guess but...

Is it an Alarm of some type?

Maybe a Reminder?

No contacts with custom ringtones. It’ll be for a period of time maybe an hour or so where any notifications that aren’t already set to silent/vibrate only, for example ESPN app, text messages, and when I click side button to lock phone, the tone will be at max volume. It’s literally happening right now, I have ringtone volume all the way down and I when I lock it, the tone will be at max volume.

I think I’ve mistaken what’s going on with yours and I have a different issue. My issue is when my ringtone is at low volume, any notifications I get will ring at max volume.

Ring volume set at low but loud ring? Do you have any contacts set with non- default custom ringtones? Just a guess!

And just like that it has stopped doing it. It’s so random. I rarely have the need to change the ringtone volume, it’ll be at low level or I’ll just put it on silent.