Stop BLE

Hi everyone!
I'm using Arduino Nano 33 BLE sense.
I'm trying to connect some devices with a host, and it works quite well. to save energy, I'd try to deactivate ble, but this seems to fail.

in usual time, no BLE, 3.3V on 3.3V power pin, I use 1.7mA. When it connects, I use something like 7mA.
Then I stop connection, I come back to 2.3mA, and I cannot enable again the connection.

To start the connexion, I use
BLE.begin()
To stop the connexion while connected, I use:
BLE.end(), but I can't check if this last function worked.
When I start again BLE.begin(), this function fails(no more info).

Before the end function, I don't disconnect: it seems to be blocked in this disconnection function.

Please, dow to disconnect in a proper way? do you have some exemple?

Thanks a lot!