how can I see the UNDERSCAN slider on the display by default - to see it always.

hello,

I've connected my AppleAir M1 (2021) by HDMI cable to the old TV. In the display setting, I had to change UNDERSCAN scale on the slider to fit mac screen into TV. On the next day I connected my M1 to screen at work and the screen "remember" the UNDERSCAN settings from TV, so the screen at work has a black frame now. Unfortunately in the display settings, I can't see the UNDERSCAN slider anymore to adjust the screen. How to fix this?!