This has been bugging me for some time and I'm just wondering why it
happens.

I have a simple formula in cell D16 that multiplies numbers in two
other cells: =C16*A16

If I manually change the value in C16 the result in D16 is correct.
If I copy/paste a value into C16, again, the result is corect.
If I CUT/Paste a value into C16 then the formula changes to
=#REF!*A16.

Is there maybe a setting I have enabled that causes this or is it
working as designed? If so, what is the logic behind the Cut/Paste
that causes the #REF???

Thanks gang! This is no big deal, I'm just curious.

Hi Big Slick,
Looks like normal Cut/Paste behaviour, but I can't see the logic behind
it.
I do know that another difference between Cut and Copy of formulas is
that the pasted result after Cutting has the same original cell
addresses, while after copying the cell addresses change unless they
were absolute eg if the formula in A1 is =B1 + $B$2 then cut/paste
into A2 it doesn't change, while copy/paste into A2 and it changes to =
B2 + $B$2. This behaviour can be useful when you want to use a formula
in another part of the sheet without its cell addresses changing.
Ken Johnson