We are currently addressing an issue where the TRX+ firmware version 4.19 can lock up and become unresponsive to the control knob. The display may still operate but the user is unable to change any settings of turn the unit off.
The only current solution is to wait for the battery to completely drain. When the TRX is recharged it will work normally again.
We are currently working on a firmware fix which will be available in the next firmware release.