i upgraded my old streaming stick to a Roku Express 3960RW and the incompatibility started on day one. Please refer to my reply to Mal4romcal for the whats and how it's now fixed!
Hi, my problem was with the Roku Express 3960RW streaming player, don't have a Roku TV. Please refer to my reply to Mal4romcal elsewhere in my post for the description. It seemed to reset itself after 3 days of having to redo the display settings
p.s. I should have been clearer. I have a Roku Express streaming device, not a Roku smart TV. I am having the problem with what the Roku box is sending to my (vintage Pioneer plasma) TV via HDMI.