Incorrect results using parameter in SSRS - sql

Question

I have an SSRS report for which I created two datasets for. One for the actual report and one for the parameter.
Dataset 1 is the report
Dataset 2 simply pulls the parameter that I want to report on from the table where it is stored.
When I run the report and select the parameter, it shows me all the values, but when I select one, I still get every record rather than just the records based on the parameter.
Dataset 1
SELECT stk.ItemCode AS ItemCode, stk.warehouse AS warehouse,
stk.Description AS Description, stk.Assortment AS Assortment,
Items.Class_02, stk.ItemGroup AS ItemGroup, stk.ItemStatus AS ItemStatus,
stk.ItemUnit AS ItemUnit, ISNULL((SELECT TOP 1 dbo.bacoSalesPrice(p.ID,
0) FROM staffl p WHERE ({d '2019-05-27'} BETWEEN validfrom AND
ISNULL(validto,{d '9999-12-31'}))
AND prijslijst = 'SALESPRICE' AND Items.ItemCode = artcode ORDER BY
artcode, validfrom desc),0) AS SalesPackagePrice,
ROUND((stk.Stock/stk.SalesPkg),2) AS Stock, ROUND((stk.Stock +
stk.QtyToBeReceived - stk.QtyToBeDelivered)/stk.SalesPkg,2) AS
AvailableStock, stk.SearchCode AS SearchCode FROM Items INNER JOIN (
SELECT
v.magcode AS warehouse,
MAX(i.itemcode) AS ItemCode,
MAX(i.description_0) AS Description,
i.SearchCode AS SearchCode,
MAX(ia.Assortment) AS Assortment,
MAX(ia.Description_0) AS ItemGroup,
MAX(CASE
WHEN i.condition = 'A' THEN 'Active'
WHEN i.condition = 'B' THEN 'Blocked'
WHEN i.condition = 'D' THEN 'Discontinued'
WHEN i.condition = 'E' THEN 'Inactive'
WHEN i.condition = 'F' THEN 'Future'
END) AS ItemStatus,
ISNULL(MAX(a.purchasepackage), '-') AS ItemUnit,
MAX(i.SalesPackagePrice) AS SalesPackagePrice,
MAX(v.bestniv) AS Minimum,
MAX(v.maxvrd) AS Maximum,
MAX(i.lev_crdnr) AS Supplier,
MAX(a.DeliveryTimeInDays) AS DeliveryTime,
MAX(ISNULL(a.SlsPkgsPerPurPkg,1)) AS SalesPkg,
ISNULL(Actual.Quantity,0) AS Stock
,ISNULL(SUM(QtyToReceived),0) AS QtyToBeReceived
,ISNULL(SUM(QtyToBeDelivered),0) AS QtyToBeDelivered
FROM items i
JOIN voorrd v ON i.itemcode=v.artcode
LEFT JOIN itemaccounts a ON i.itemcode=a.itemcode and i.lev_crdnr=a.crdnr
AND i.itemcode IS NOT NULL AND a.itemcode IS NOT NULL AND i.lev_crdnr IS N
NOT NULL AND a.crdnr IS NOT NULL
JOIN ItemAssortment ia ON ia.Assortment = i.Assortment
LEFT OUTER JOIN
dbo.TempToBeReceivedDelivered#3E5BBBE6#FB7B#4309#9CE1#560885B9BF94# budget
ON v.magcode = budget.warehouse AND i.ItemCode = budget.artcode
AND v.magcode IS NOT NULL AND budget.warehouse IS NOT NULL AND i.ItemCode IS NOT NULL AND budget.artcode IS NOT NULL
LEFT OUTER JOIN
(SELECT GX.artcode, GX.warehouse,
GX.Quantity,
GX.AmtActualStock, GX.TotalCnt,
CASE WHEN GX.FreeQuantity > GX.CurrentQuantity THEN (CASE WHEN GX.CurrentQuantity < 0 THEN 0 ELSE GX.CurrentQuantity END) ELSE
(CASE WHEN GX.FreeQuantity < 0 THEN 0 ELSE GX.FreeQuantity END) END As FreeQuantity
FROM (
SELECT sb.ItemCode AS artcode, SUM(CASE WHEN sb.Date <= {d '2019-05-27'} THEN sb.Quantity END) as Quantity,
ROUND(SUM(CASE WHEN sb.Date <= {d '2019-05-27'} THEN sb.StockAmount END),2) as AmtActualStock,
SUM(CASE WHEN sb.Date <= {d '2019-05-27'} THEN sb.Quantity END) as CurrentQuantity,
SUM(CASE WHEN sb.Date <= {d '2019-05-27'} THEN sb.FreeStock END) AS FreeQuantity, sb.Warehouse,
SUM(sb.GbkmutCount) AS TotalCnt
FROM StockBalances sb WITH (NOLOCK) JOIN Items ON sb.ItemCode = Items.ItemCode JOIN ItemAssortment ON Items.Assortment = ItemAssortment.Assortment
--WHERE Items.Class_02 in #Customer
GROUP BY sb.ItemCode, sb.WareHouse, Items.Class_02
HAVING SUM(sb.GbkmutCount) > 0) GX) AS Actual
ON Actual.artcode = i.ItemCode AND Actual.warehouse = v.magcode AND Actual.artcode IS NOT NULL AND i.ItemCode IS NOT NULL AND Actual.warehouse IS NOT NULL AND v.magcode IS NOT NULL
WHERE i.type IN ('S', 'B')
AND i.ItemCode BETWEEN '0030122186' AND 'XS45000'
AND i.Condition IN ('A')
AND ((i.IsSalesItem <> 0)) AND i.Type IN ('S', 'B')
AND 1=1
GROUP BY v.magcode , i.itemcode, i.SearchCode, Actual.Quantity
) stk ON items.ItemCode = stk.ItemCode
INNER JOIN grtbk ON Items.GLAccountDistribution = grtbk.reknr
ORDER BY stk.ItemCode
Dataset 2
SELECT Class_02, ItemCode FROM Items
Parameter in SSRS is set to Get values from Query, Value field: Class_02
Label field: Class_02