Receiving empty Buffer in characteristic.on()

[TIB28]

When subscribing a characteristic it give an empty buffer.

Here is my code running on rpi4 with Debian Buster:

await characteristic.startNotifications()
characteristic.on('valuechanged', buffer => {
  console.log(buffer) // Show empty Buffer: <Buffer >
})

await characteristic.readValue() // Trigger the callback

[TIB28]

Found out that my BLE sensor was faulty.