As per the recent Reddit post, some of the Hotkeys cannot be assigned as shortcuts and the Screenshot shortcuts do not work at all no matter which shortcut combo is selected.
My Xiaomi Mibook has media hotkeys for media (volume uo/volume down/mute) and dedicated key for screenshot. All of this cannot be assigned directly. When I try to assing media key for mute for example, it disables the key. I can however assign the mute key in combination with some other key (e.g WindowsKey+MuteKey) and it works fine.
The kernel has the correct keys assigned however.
xdev for the mute key gives the following debug info: KeyPress event, serial 37, synthetic NO, window 0x3400001, root 0xb5, subw 0x0, time 4059162, (10,-14), root:(751,360), state 0x0, keycode 121 (keysym 0x1008ff12, XF86AudioMute), same_screen YES, XLookupString gives 0 bytes: XmbLookupString gives 0 bytes: XFilterEvent returns: False
xmodmap -pke confirms that they key number observed in xdev is indeed assigned the mute function: keycode 121 = XF86AudioMute NoSymbol XF86AudioMute
dconf-editor, also confirms that the correct audio functions are assigned