Every morning when I turn on the TV on my roku express 4k+ I have to go through the entire set up again like it is just out of the box. It is updated with newest software. I can't find an email address or a live chat to actually get help and it is very frustrating.
Try using the included power adapter plugged directly into wall outlet rather than using the TV's USB power port if so configured.
If you are experiencing the same issue using wall power supply, then you most likely have a failed/bad device. If device is new (30 days), return to place of purchase and swap out for a new one. If device is less than a year old, should qualify for warranty replacement.