Why do I have to choose the language every time when I go into the recovery mode?

My MacBook Pro is 16 inch bought from 2019 and the macOS version is Big Sur. Last week, **I reset the nvram** then I found I have to choose language option every time I go into recover mode (by using Command + R after boot). Before that, I don't need to choose any language option when I go into the recover mode. That's so weird because I don't think I'm suppose to choose language every time. What I tried: Go to recover mode again, choose the language, and enter the password of User account. Then reboot machine, go to the recover mode, still found I need to choose the language. Is there any idea that can solve this issue?