Just installed roku express + on tv. Using hdmi port 1. When I power the tv back on, the signal from roku isn't showing up on the screen. Hdmi port 1, shows that roku is plugged in, but no signal. I have to switch to another input, then back to hdmi 1 and roku home screen shows up.
This happens every time I power off the tv and turn it back on.
Assuming you have gone through the Setup Settings and they are correct...sometimes that happens to me, [No internet connection] although not every time, and I just go thru the options settings menu and restart Roku...may take 30 seconds or so for it to connect to the internet...every now and then I have to do that.
But sounds like your box is asleep and switching cables back and forth somehow wakes it up. I don't know about that. I just happened to be passing by...hope you get a sure fix!
I would hazard a guess that it's because the Roku is 'asleep' when you turn your TV on. Asleep may not be the correct term, but my projector wouldn't see an HDMI signal from the Roku until I pressed a button on the Roku remote and the light on the Roku was lit. I suggest pressing the home button on your Roku to wake it up before turning on the TV, and see if that solves it for you.