Bluetooth precense not working


I succesfully installed raspian and a supervised version of home assististant on a rasperry pi 1 and now I am trying to make the bluetooth donge to work. It is a 8723b chipset from realtek. I installed the module and the dongle is recongised by the system.

lsusb gives me
Bus 001 Device 004: ID 0bda:b720 Realtek Semiconductor Corp.

hcitool dev gives me
hci0 20:0D:B0:20:6B:C9

but hcitool scan just gives me
without any results

I am notising that the known_devices.yaml is not created. (creating it manually also does not help)
And bluetooth is detection is not working.
I know the settings are ok since I tried the same dongle and setting with the vdkms image.

Can anyone help?

Kind Regards