Quartiles not working as expected. Qlik scripting

[Vern2022]

Can somebody please tell me why my Quartiles are not working correctly? If you look at the top table provided.

You will see the top quartile sometimes has a lower number than the middle quartile.

You will see from the bottom table provided that Q1, Q2 show as 0 where as Q3 contains a number. This is also true when I set them as dimensions oppose to measures.

your help is appreciated.

This is what is in the script:

[SalesFunnelEvents]:

LOAD
EventDate,
EmployeeNumber,
aardate,
AvailableSeconds,
NetAvailableHours,
NetAvailableSeconds,
TotalCallsIn,
TotalCallsOut,
TotalTalkIn,
TotalTalkOut,
TransactionType,
AccountNo,
cdhtTransDate,
if(isnull(DeliveryMargin), 0, DeliveryMargin) as DeliveryMargin,
DeliverySalesValue,
if(isnull(DeliveryVolume), 0,DeliveryVolume) as DeliveryVolume,
oDateCreated,
olRowid,
OrderConvertedQuantity,
OrderTotalMarginGBP,
qDateCreated,
qlRowid
From

[lib://.qvd](qvd);

[SalesFunnelEventsNew]:


join(SalesFunnelEvents)
LOAD

Fractile(DeliveryVolume, 0.25) as DeliveryVolumeQ1,
Fractile(DeliveryVolume, 0.50) as DeliveryVolumeQ2,
Fractile(DeliveryVolume, 0.75) as DeliveryVolumeQ3,
Fractile(DeliveryMargin, 0.25) as DeliveryMarginQ1,
Fractile(DeliveryMargin, 0.50) as DeliveryMarginQ2,
Fractile(DeliveryMargin, 0.75) as DeliveryMarginQ3

resident SalesFunnelEvents; 

//In the back ground colour expression for the measure itself



    =if(Dimensionality() = 3 and (match([Month Offset], '0', '-1', '-2', '-3', '-12'))
    , if([Delivery Volume] <= sum([DeliveryVolumeQ1]), red(),
        if([Delivery Volume] < sum([DeliveryVolumeQ3]) and [Delivery Volume] > sum([DeliveryVolumeQ1]), blue(),
          if([Delivery Volume] >= sum([DeliveryVolumeQ3]), green()))
      )
 )

Many thanks