Contour boxes still locking up...

I know this has been posted several times, but the dates on some of the similar posts are in 2014, and describe the exact problem I'm having today in 2017. At least 3 times a week, our contour boxes lock up for anywhere from one to seven minutes, and you can't change the channels at all. No buttons work on the remote (except volume). You can't even press any buttons on the box itself, including the power button. Several times I've had to unplug the box from the wall, then you have to wait on the 15 minute boot-up process. We have two boxes in our home and they both lock up and unlock at the same time. I've brought one of the boxes back thinking it was the problem, but the new one does it as well.