As you can see, I am a new member to the forum and a new user of Torque Pro – so my suggestion may be a bit lame.
I was using Torque Lite and to turn it off I just used the Android approach to closing the App. When I went to reconnect I just hit the screen icon and I would get prompt connection to the ECU. When I purchased Torque Pro, I initially got connection but afterwards it just did not connect at all. I discovered that if I did a forced stop in the Android App settings it would connect the next time I tried (ie. until this something was running in the background). Subsequently, I discovered there is a “Quit” command within the App settings. If I use this each time, the App “seems” to fully shut itself down and is ready to do a proper connection the next time. If you are not using this “Quit” command – give it a try. If you have known about this forever – then please excuse my attempt to help.

Good luck
Larry