URL: http://localhost:8080/odata4/olingo_basic/Source/Customers/?$count=true&$expand=Orders_FK0
Expected count: 4
Actual count: 9

Similar behavior with $filter - http://localhost:8080/odata4/olingo_basic/Source/Customers/?$count=true&$filter=idcust%20lt%203&$expand=Orders_FK0

OData should return only count of Customer entities.