iPhone Automatically Reduces Ringtone Volume When Connecting Bluetooth Devices

Hi, I’m experiencing an issue with my iPhone’s ringtone volume when using Bluetooth devices. Recently I've been noticing that my ringtone volume would automatically drop to around 50–60% whenever I connect to my bluetooth earbuds.

I didn't notice it before cause I wasn't using earbuds as frequently as i do now. However, i think I had manually set this up myself (not through an automation in the Shortcuts app, cause if it was the case i could see it in the automation menu in shortcut app). Now, I’ve switched to using QCY earbuds, and I notice this happening frequently since I use them more often. The volume decreases as expected when I connect the earbuds, but it doesn’t return to 100% after disconnecting. And i don't think it's a feature of the bud, cause i don't see any option like this in the QCY app. To be honest, I’m not sure if it ever returned to 100% before, but I’d like it to work that way now.

The problem is I can’t find the option in Settings anymore. Could someone guide me on how to make my iPhone automatically reduce the ringtone volume when a Bluetooth device connects and return it to 100% when it disconnects?

Btw, i use and iPhone 13.

[Edited by Moderator]