Using summarize gives wrong value

Hi everyone,

I am having some issues with the Summarize function as it is not giving the correct value for a specific measure. I'll explain below.

I have a sample HR table where a person has one row/record per month.

I have the following calculation:

MyCalculation = COUNTX(
                FILTER(
                    SUMMARIZE('Sample data';'Sample data'[userID];
                    "Leave";SUM('Sample data'[leaveDays]);
                    "UnitChange";CALCULATE(DISTINCTCOUNT('Sample data'[Unit]);ALL('Sample data'[Unit])));
                [Leave]<=2 && [UnitChange]<2);
            [Leave])

The bolded part above is supposed to count how many Units a userID has belonged to(as per the summarize function). 

However, upon inspection all userIDs get assigned value 1 on UnitChange(1 is the least they can have) even in cases where they actually have a higher number.

So Summarize does not seem to calculate the correct value for the UnitChange measure.. 
I've been stuck on this for a while now.. Anyone have an idea? 
Thank you