Phone rings in bluetooth headset that it is not connected to
I'm having a very puzzling issue. I have my phone on silent and when I receive a phone call, it rings in my roommate's Bluetooth headphones. These headphones are not connected to my phone, and as far as I'm aware they never have been. No other sounds from my phone play through these headphones and neither does the call audio. This happens even when I have Bluetooth turned off. If I connect a different Bluetooth headset, the call rings in both. Anyone have any idea what might be happening or how to fix it?
iPhone 11