System update 2-19-2020 changed auto detect on refresh rate to disabled.
I was watching Roku, stopped for an hour or so, came back to continue my program and my TV would not recognize the device. It showed nothing on my HDMI port. I eventually put the Roku on another TV that had a working Roku just like the one that was failing. It worked. I took the Roku from that TV that was working and put it on the TV that was not recognizing it. Swapped out cables, nothing. Did reset on TV, nothing. Checked settings on Roku .. using a working TV and saw that an option didn't look right. It was in the advanced settings. The auto detect refresh rate was set to disabled. I enabled it and problem solved. So I checked my second Roku Premier and it was also disabled and also failed on the same TV. I enabled it and it was ok as well. I had not touched any settings on either Roku Device since my initial setup. The only conclusion I can come to is the latest build modified it.
Roku Premier/Samsung 6 55 TV/Software Version 9.2.0 build 4807