Drag tool to adjust formulas correctly

Hi,

I did once this some time ago, but now I cant find how I did it, perhaps someone can help with advice.

I want to copy/drag fields including merged cells, blank cells etc. but keeping the formulas and that formulas are adjusted correctly, i.e. From cell B3 to B4 when dragged, etc. But it works only if there is one cell in the formula linked to, it is not working if more than one cell used in formula, excel update only the last cell in formula. See example attached.

Any advice how to fix this with drag down tool?

Thanks!

As soon as I read 'merged cells' I quit.