It sounds like your computer may be defaulting to the HDMI connection as the primary display instead of the RGB connection. Here are some steps you can try to fix this:
- Right-click on the desktop and select "Display settings" from the menu.
- Under "Select and rearrange displays", you should see both your base monitor and your TV. Click on the TV.
- Scroll down and click "Advanced display settings".
- Under "Multiple displays", select "Extend desktop to this display" for the RGB connection.
- Make sure that "Duplicate desktop on 1 and 2" is not selected.
- Click "Apply" and then "Keep changes" when prompted.
This should set the RGB connection as the secondary display and allow you to use the HDMI connection as an auxiliary for movies and other media.
As for changing the input on your TV, you can try using the remote to switch between the RGB and HDMI inputs. If this is inconvenient, some TVs have an option to automatically switch to the active input. You can check your TV's manual to see if this is possible.
I hope this helps! Let me know if you have any further questions.