FWIW:

In cells B10:D10 I have 111, 222, 333
In Cell D4 I have 3
In cell D6 I have =sum(b10:Offset(b10,0, D4-1))
which displays 666 << which is correct.

But if in the formula bar (on cell D6) if I highlight
(evaluate) the portion Offset(b10,0, D4-1) and
press F9 it equates to 333
Showing =sum(b10:333) << Which of course is not
a valid formula
So "D10" is being returned, versus the Value of D10

Just thought I'd pass along this recent (todays) enlightenment to those in
the group that didn't already know..