Oppo
Turn Contact Sharing via Bluetooth On or Off auf Oppo
When two devices connect over Bluetooth, contact sharing is a separate permission from the pairing itself. Coloros treats it as an individual setting for every paired device, which is why a car system, headset, or second phone might not receive your contacts even though the Bluetooth connection works fine.
To change this, open Settings ➔ Bluetooth, then tap the Select a Paired device entry for the device you want to adjust. Inside that device screen, look for the option to Enable or disable Contact sharing and toggle it to match what you need.
Turn this option on if you want your contact list to sync automatically to a car infotainment system or a compatible accessory, so incoming calls show a name instead of just a number. Turn it off if you share a Bluetooth connection with a device you do not fully trust, or if you only need audio or file transfer without exposing your address book.
This setting only affects sharing over Bluetooth. It has no effect on contacts synced through a Google account or transferred via cable, and disabling it does not remove contacts already copied to the other device.