If holding down shift + 5 will return an Input with its keycode as Enum.KeyCode.Unknown
EDIT:
It seems like the following keys return Enum.KeyCode.Unkown
~ = shift + `
! = shift + 1
@ = shift + 2
# = shift + 3
$ = shift + 4
% = shift + 5
^ = shift + 6
& = shift + 7
( = shift + 9
) = shift + 0
_ = shift + -
{ = shift + [
} = shift + ]
| = shift +
: = shift + ;
< = shift + ,
> = shift + .
? = shift + /
EDIT2: Appears to happen on windows too