Hello
I've managed to send a file using Bluetooth. First to get bluetooth running again, I've reset the device.
After this, bluetooth service worked again normally.
As advised by @gpatel-fr, I've installed bt-obex using crackle.
crackle install bluez-tools
I've then opened 3 Terminal tabs to run these tasks in parallel:
Terminal 1
# To find the Android phone receiving the file
bluetoothctl
scan on
# Find and copy the MAC address of the Android bluetooth adapter to paste it in terminal 3
Terminal 2
# Start the obexd tool
/usr/libexec/bluetooth/obexd
Terminal 3
# Make sure that the Android bluetooth device is discoverable
# Send the file with bt-obex
bt-obex -p [MAC address of the Android bluetooth adapter] /tmp/test-bluetooth.txt
On the Android device, make sure that you accept receiving the file from the Ubuntu Touch device and check that the content is sucessfully received.
but I often get the pop-up reminding me to disable the Wi-Fi even if it is already disabled. Switching the Wi-Fi and cellular toggles on and off usually unblocks MMS sending.