Measure returning data only when using smaller than operator

There might be an obvious solution for this topic, but I just dont see it:

I have a datasource looking like this:

Then I want my measure to count the number of customers having their first order placed this year, using the MIN-function on OrderDateID,saying it should be larger than the measure M_LastDatePreviousYear. And then filter by CAM (Customer Account Manager).
Should be easy, like this:

M_NumberOfNewCustomersByCAMThisYear =

//Converting measure to variable
// (M_LastDatePreviousYear = 20231229, tested using both dynamical and static value)

VAR var_M_LastDatePreviousYear = [M_LastDatePreviousYear] 

RETURN CALCULATE(DISTINCTCOUNT(Customers[CustomerID]),
FILTER(Customers,MIN(Customers[OrderDateID])>var_M_LastDatePreviousYear),
FILTER(Customers[CAM]=[M_SelectedUSer])
)

However, this always returns a blank measure.
But if I change the operator like this:
FILTER(Customers,MIN(Customers[CreatedDateID])<var_M_LastDatePreviousYear),

it returns the number of customers having their first order before M_LastDatePreviousYear

I can also insert a table visual, and display all customers having their first order this year in the way shown above. So there are customers fulfilling my spec, I just want to count them 🙂

Anyone who can enlighten me on this one?

Regards,

John Martin