I needed to change the report from using a query JmgPaySpecification to using the query JmgPaySpecificationExt instead.
I started out by changing the
attribute in the classdeclaration of the RDP class and compiling it.
Then I went to Visual Studio, opened the report and doing a rebuild on it to get it refreshed in the AOT.
This clears the Query setup.
Repeating the find on the SSRS-report searching all nodes and searching for JmgPaySpecification revealed: