Assuming that vReloadDate and YEAR are behaving correctly, then this looks like a model structure issue. The first statement is looking at a single table, but I suspect that offertes.OffDate and/or YEAR are in a table different to offertes.Offline.
Then the problem is that the association between the tables is not one to one, so that there may be two rows in the second table for each row in the first. When you incorporate a field from the second table in the expression, it will count the expression for each row in each table, hence 6 in the second count.
If that does not help, then I suggest that you post your model or a sample so that it can be looked at in more detail.
Hope that helps
Year is indeed in a different table, but offertes.offdate is not. I added the qvw so you can see for yourself. Maybe there are things I did not mention for you.
Thank in advance
sample.qvw 5.7 MB
Quick and dirty analysis - the expression routes through to the calender to get to JAAR
Tables offertes has 78400 rows, but only 21824 distinct values of OfferteKey
The link table has 37984 rows with values of OfferteKey, so some values appear more than once in the link table
Because the OfferteKey is not unique in the link table, it will count multiple possible values if you go via the LinkTable to execute the expression.
Another way of structuring your model might have been to concatenate the Orders, Offertes and Invoices table into a single fact table, or if that is not possible, to have separate calendars for each table. If you want to use a link table, then ensure