Known Bluez issues

• Connecting to devices with a random address only works while discovery is running
• In Bluez 5.55-5.63, when writing a characteristic with 'write with response' property, it always returns ERR UNLIKELY. Fixed in Bluez 5.64

Attribute caching

By default it is done for all devices. You can modify /etc/bluetooth/main.conf to change this behaviour. See main.conf

To manually delete the cache, remove the cache directory in /var/lib/bluetooth/[adapter]/cache

Disable battery plugin

Modify /lib/systemd/system/bluetooth.service by changing this line:

ExecStart=/usr/lib/bluetooth/bluetoothd -P battery

Disable ReverseServiceDiscovery to avoid connections being made to iOS/Android/Other devices

Try to set ReverseServiceDiscovery = false in the /etc/bluetooth/main.conf file.

When ReverseServiceDiscovery is enabled, BlueZ (acting as a peripheral) attempts to read characteristics from the Android/iOS device (acting as a central). However, certain characteristics, such as battery level, require higher security levels, which may trigger a pairing request.