I have a 55' tcl roku tv that keep resets everytime I go to activate my device. Ive unplugged it for a fews to reset it and tried holding down the reset button for half a minute to a minute. The tcl tv is just over a year old
Do you have "Fast start" enabled on your Roku TV? If not, see if that prevents the problem.
Settings | System | Power | Fast TV start
Fast start is not an available setting for my tv.