Failed to connect to peripheral xx:xx:xx:xx:xx:xx, addr type: random/public about bleah

[0x5ECF4ULT]

Same issue here. I use my internal WLAN/Bluetooth adapter.

[0x5ECF4ULT]

Update: I bought a Bluetooth adapter. Program works without problems. The issue you have is most likely because some process is using your adapter. Is it the only hci on your computer?

You could try:

sudo service bluetoothd stop
sudo hciconfig hci0 down
sudo hciconfig hci1 down (if you have a second adapter)
sudo hciconfig hci0 up
sudo hciconfig hci1 up
sudo service bluetoothd start

Please give me feedback to this solution!
Note: There is no right solution in the Bluetooth world. What a shitty protocol...