I used both the earlier bluez version of 5.37 and the latest 5.50. facing similar issue of connecting and disconnecting.
This is the log: of bluetoothctl
bluetoothd[11417]: src/adapter.c:connected_callback() hci0 device XX:XX:XX:XX:XX:XX connected eir_len 18
bluetoothd[11417]: src/device.c:device_create() dst XX:XX:XX:XX:XX:XX
bluetoothd[11417]: src/device.c:device_create() dst XX:XX:XX:XX:XX:XX
bluetoothd[11417]: src/device.c:device_new() address XX:XX:XX:XX:XX:XX
bluetoothd[11417]: src/device.c:device_new() Creating device /org/bluez/hci0/dev_XX_XX_XX_XX_XX_XX
bluetoothd[11417]: src/device.c:device_set_class() /org/bluez/hci0/dev_XX_XX_XX_XX_XX_XX_0x5A020C
[NEW] Device XX:XX:XX:XX:XX:XX Arctic Wolf
bluetoothd[11417]: src/adapter.c:new_link_key_callback() hci0 new key for XX:XX:XX:XX:XX:XX type 4 pin_len 0 store_hint 1
bluetoothd[11417]: src/device.c:device_set_bonded()
bluetoothd[11417]: src/device.c:btd_device_set_temporary() temporary 0
bluetoothd[11417]: src/device.c:device_bonding_complete() bonding (nil) status 0x00
bluetoothd[11417]: src/device.c:device_bonding_complete() setting timer for reverse service discovery
bluetoothd[11417]: src/adapter.c:resume_discovery()
bluetoothd[11417]: src/adapter.c:add_whitelist_complete() XX:XX:XX:XX:XX:XX added to kernel whitelist
bluetoothd[11417]: src/device.c:device_probe_profiles() Probing profiles for device XX:XX:XX:XX:XX:XX
bluetoothd[11417]: src/device.c:device_svc_resolved() /org/bluez/hci0/dev_XX_XX_XX_XX_XX_XX_ err 0
bluetoothd[11417]: src/adapter.c:dev_disconnected() Device XX:XX:XX:XX:XX:XX disconnected, reason 2
bluetoothd[11417]: src/adapter.c:adapter_remove_connection()
bluetoothd[11417]: src/adapter.c:bonding_attempt_complete() hci0 bdaddr XX:XX:XX:XX:XX:XX type 0 status 0xe
bluetoothd[11417]: src/device.c:device_bonding_complete() bonding (nil) status 0x0e
bluetoothd[11417]: src/device.c:device_bonding_failed() status 14
bluetoothd[11417]: src/adapter.c:resume_discovery()
[CHG] Device XX:XX:XX:XX:XX:XX Connected: no
Hi:
There is a method for BBGW’s pairing bluetooth. Here are commands:
sudo su
bluetoothctl
power on
agent on
default-agent
scan on
If you want to connect device, you could refer to these commands:
scan off
pair
trust
connect
If you still cann’t solve it, please contact me.