I have two different hosts on two different kernels with the same application written by me. I tried to make BlueZ exactly the same, 5.64. I see no difference in configuration. The application sets trusted to true before pairing. On one host, bluetoothctl must be running, even though there is no prompting to pair in bluetoothctl. On the other host, pairing occurs without bluetoothctl running. kernels are 5.4.199 versus 5.10.120. 5.10.120 has the issue with a bluetoothctl requirement. John Klug
