Why is macOS choosing the wrong display to mirror when using the Command+F1 shortcut to switch between extending and mirroring?

I have the 2021 MacBook Pro, macOS Monterey 12.0 I have an external monitor hooked up to my MacBook. I use the MacBook as the "Main Display" and therefore the dock shows up on the MacBook screen. If I use the shortcut Command+F1, (the shortcut switches between Mirroring and Extending the display), it makes my external display the Main Display and starts mirroring my external display on to the MacBook." My external display is an ultra wide so it makes the MacBook display weird, since it "optimizes" for the Main Display. I'm not sure why it changes the Main Display? Is there a way to prevent that or a shortcut to switch the Main Display? If I use the shortcut again, it goes back to normal with the MacBook screen being the Main Display. Any app that can make switching also would help!