Yes. Starting with iPhone 11, iPhones basically act or AirTags when powered down unless the switch for the Find My Network has been disabled in Settings > (name) > Find My > Find My iPhone.
The cellular modem is off which is why it sent as an SMS, but the low energy Bluetooth functionality is still allowing other nearby devices to see it and relay its location.
Yes. Starting with iPhone 11, iPhones basically act or AirTags when powered down unless the switch for the Find My Network has been disabled in Settings > (name) > Find My > Find My iPhone.
The cellular modem is off which is why it sent as an SMS, but the low energy Bluetooth functionality is still allowing other nearby devices to see it and relay its location.