Hi Francesco I tried to determinate what is happening looking at the attachment but it's difficult, could you share the excel with the table so I can check what range of data belongs to each tendency line?
The problem is that the serie that generates the tendency has filled out with zero until end of year, so the tendency is showing that, to solve this you have to empty the rest of the year, so the tendency only get calculated over the real data. Try that and let me know if works
@FrancescoBarcelona Hi Francesco, I'm not an expert so I cannot tell you that's the definitive solution, but, based on how the tendency line is calculated, I think it is. Remember that zero's affect the calculation.
You can use a IF function to ask if there is a data for a specific cell, if true you put the formula if don't you put "blank" maybe that could help you.