You have two Roku devices, not one.
Your Roku TV has its own menu, and it includes the various inputs. One of your inputs is the HDMI port to which your other Roku, the Streambar, is connected.
The Streambar doesn't have the inputs, because only Roku TVs have those, and the Streambar is not a Roku TV.
So, when you're watching via your Streambar, you get the Streambar menu, which is simply a standard Roku menu.
When you're watching via your Roku TV, you will get the Roku TV menu, which includes inputs.
Imagine if you connected a Fire TV device to your Roku TV. When you switched to the HDMI input for the Fire TV, you'd see Fire TV menu, not Roku TV menu. Same thing. Roku devices don't have inputs. Roku TVs do.
You can watch through your Roku TV and listen via the Streambar, if configured properly (usually via HDMI/ARC). But if you choose to watch via Roku Streambar, you won't see the Roku TV menu, because you're on a different Roku device.
Roku Community Streaming Expert
Note: I am not a Roku employee.
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