M1 MBA - Fn + Function Keys Not Working

My M1 MBA has Big Sur 11.1 pre-installed out-of-the-box. I have enabled “use f1 f2 etc. keys as standard function keys”.

Pressing fn + different function keys supposedly gives different commands, such as volume and playback controls. However, this won’t work when I attempt to enable/disable Do Not Disturb (fn+f6), Siri dictation (fn+f5) and the remainder except volume (fn+f10/f11/f12) and playback controls (fn+f7/f8/f9).

I tried the M1 MacBooks in Apple Store. All of them have the same issue.

Anyone having idea how I can raise this issue to Apple?