Der Stick ist in Ordung, hab Ihn in ein anderes System getestet.

root@rock:~# sudo service bluetooth status
● bluetooth.service - Bluetooth service
   Loaded: loaded (/lib/systemd/system/bluetooth.service; enabled; vendor preset: enabled)
   Active: active (running) since Tue 2020-05-05 10:39:18 CEST; 1s ago
     Docs: man:bluetoothd(8)
 Main PID: 12414 (bluetoothd)
   Status: "Running"
    Tasks: 1 (limit: 4746)
   Memory: 2.3M
   CGroup: /system.slice/bluetooth.service
           └─12414 /usr/lib/bluetooth/bluetoothd

Mai 05 10:39:17 rock systemd[1]: Starting Bluetooth service...
Mai 05 10:39:18 rock bluetoothd[12414]: Bluetooth daemon 5.50
Mai 05 10:39:18 rock systemd[1]: Started Bluetooth service.
Mai 05 10:39:18 rock bluetoothd[12414]: Starting SDP server
Mai 05 10:39:18 rock bluetoothd[12414]: kernel lacks bnep-protocol support
Mai 05 10:39:18 rock bluetoothd[12414]: System does not support network plugin
Mai 05 10:39:18 rock bluetoothd[12414]: Bluetooth management interface 1.14 initialized

root@rock:~# lsusb | grep -i bluetooth
Bus 001 Device 002: ID 0a12:0001 Cambridge Silicon Radio, Ltd Bluetooth Dongle (HCI mode)
root@rock:~# 

sudo dmesg | egrep -i 'blue|firm'
[    0.000000] psci: PSCIv1.0 detected in firmware.
[  174.158325] platform regulatory.0: Direct firmware load for regulatory.db failed with error -2
[  635.504557] Bluetooth: Core ver 2.22
[  635.504633] Bluetooth: HCI device and connection manager initialized
[  635.504649] Bluetooth: HCI socket layer initialized
[  635.504656] Bluetooth: L2CAP socket layer initialized
[  635.504673] Bluetooth: SCO socket layer initialized
root@rock:~# 

Was muss ich tun?