I'm not sure what you mean by logging in, but if you use one of the screen savers with advertisements, then pressing play when an ad is showing will typically take you to the channel being advertised. (I use one of the clock screen savers to avoid this particular feature.)
This is using the Roku stick. We always leave the Roku screen in the home position. We have multiple instances of turning the TV on, changing the input to be the Roku stick HDMI port, and finding a random program/show being run.
We have no idea why and are concerned of a possible hack.
@Minty1 wrote: We have multiple instances of turning the TV on, changing the input to be the Roku stick HDMI port, and finding a random program/show being run.
I've read stories about Roku having major security flaws. With all we see here, on the non-support forum, with software updates breaking tvs, it makes you wonder what we don't know about. Right? Anything's possible.
There should be a pinhole reset button somewhere on the Roku stick. You could do that and change your wifi password. (You should also look for a feature in your router which creates guest access points. These often have a choice to say devices connected to these guest APs can't see other guests. All your internet-of-things devices should connect to a guest access point, so they're isolated. That just adds more protection from one vulnerable device making more devices more vulnerable. If one is compromised, the intruder will be stuck there. They can't get to your Alexa-speaking toaster, or whatever.).
If the problem went away for awhile, then returned, I'd be concerned about that.
IMO, the more likely reason is that Roku will do anything for monetized events. I.e., more viewed content yielding more carriage-fees, ad sharing. They could be conveniently "oops, a glitch had you watching 4 movies last night while your tv was off." With this company, anything like that is definitely possible. You're not a customer. You're a source of "monetized events." That's the center of Roku's universe. Not customer satisfaction, or attention to details, or security. All that stuff takes a backseat to the main charter of more monetized events.
"People are often amazed at how much we’ve done with the number of engineers we’ve got." (Roku CEO Anthony Wood, Austin Statesman, Oct 4, 2019). "Amazed" is one way of putting it.