I resolved this by moving phone to my ubuntu 18 laptop. i had to add the USB device per this page: https://android.stackexchange.com/questions/144966/how-do-i-get-my-device-detected-by-adb-on-linux
Started ubtouch and it's now installing.
@isolated-thinker probably no one replied to your question because nobody knows the answer
The only thing I can tell you is that there are a lot of issues with bluetooth in UT, as you can see in "The" Bluetooth Thread.