So I’m not sure how this works, but my recorder (mirilis action) does not detect rust. Works with legacy but I can’t get it to work with the new rust. I look for help here or with the mirilis action team?
Try launching Rust by double-clicking on RustClient.exe and see if the capture can now see the main menu. Launching Rust this way will get you kicked from any server with security enabled, but the point is to see if the capture works.
If it works, your capture program is being blocked by EasyAntiCheat for the way it hooks into the game to record it. Try OBS if this is happening.