Oh man. I just found mine did the same thing . Every morning I leave the TV on for a pet before I leave for work . It automatically turns off 4 hours of idle time .
I came home today to find my TV was still in. I got scared and thought someone was in my home and turned on the TV .
I went into settings to find the option was no longer there! That's a solid feature for Verizon to remove . I tried calling Verizon but there is a 2 and a half hour hold time. I'm going to soon switch providors anyway...