Bluetooth stops discovering devices after inactivity (Realtek USB, Lenovo IdeaPad)

[mikesosacr]

Description:
On Zorin OS CORE (based on Ubuntu 22.04/24.04), Bluetooth stops discovering any devices after a period of inactivity or suspend on Lenovo laptops using Realtek USB Bluetooth (0bda:4853).

Symptoms:

• bluetoothctl scan on starts but no devices are discovered.
• hciconfig shows the controller as UP RUNNING.
• rfkill list shows no soft or hard blocks.
• Rebooting does not restore Bluetooth functionality.
• Only a full power-off (disconnecting all power) restores Bluetooth discovery.

Hardware:

• Lenovo IdeaPad 1-15IAU7
• Realtek USB Bluetooth 0bda:4853

Workaround / Temporary Fix:

• Manually reload the btusb and related modules (btusb, btrtl, btintel, btbcm, btmtk).
• Disable USB autosuspend for the Bluetooth module by creating /etc/modprobe.d/btusb.conf with:

options btusb enable_autosuspend=n

• After applying this fix, Bluetooth becomes stable and continues to work even after inactivity.

Steps to reproduce:

1. Connect a Bluetooth device (e.g., speaker or headphones).
2. Let the system go idle or suspend.
3. Try scanning with bluetoothctl → no devices are discovered.
4. Only after a full shutdown and power-on, Bluetooth resumes normal operation.

Notes:
This seems to be a Realtek + USB autosuspend issue. Providing an automatic workaround in Zorin could prevent other users from encountering the same problem.