Excell function problem

It sounds like the problem you are having is how Excel handles excel formulas when you copy vs when you cut&paste  or move.  Since you didn't include more information like the formulas and the data structure and a copy of the sheet I will have to just use an example to explain the concept.

So first, excel will do its best to guess how you want to modify your formula.  You have some control over this also.  If you move (or cut & paste) it will not change the references in the formula.  If you copy (or use fill) it will try to increment the references to a corresponding relative location.  So take the following simple example:

in cells A1:A3 I just have the number 1,2,3 and in cell B1 I have the formula =A1+A2

I then copied the formula down to B2 and B3 and those formulas became =A2+A3 and =A3+A4 respectively

but if I highlight A3:B3 and move it down 1 row I get:

this is because the formula referenced A3 & A4 and A3 moved to A4 so it updated that to A4 but what was A4 no longer exists as it was overwritten.