Parameter names in End-point for SQL statements

Summary: I'm fairly new to OIC Integrations and came across something that's driving me nuts, sometimes when I configure an endpoint for a SQL query it is using the actual parameter name. But other times it's just using arg1, arg2, arg3 etc. and ignores the parameter name I use in the query.

Content (required):

My question is why do I get sometimes this:

<xs:complexType name="SummarizeEmployeeHoursInput">

   <xs:sequence>

     <xs:element name="arg1" type="xs:string" nillable="true"/>

     <xs:element name="arg2" type="xs:string" nillable="true"/>

   </xs:sequence>

  </xs:complexType>

And other times this:

 <xs:sequence>

     <xs:element name="