Divide 40 GB by 722,000,000 and you'll find the result is roughly just shy of 60.   So your table can't fit in RAM unless those 22 columns average less than...

My gut says it's something in the SQL syntax...  I'd also check the values for the Options on the Linked Server, and be sure to set RPC and RPC Out to...

Okay, let's try another shot at the syntax on the OpenEdge side:
SELECT CONVERT(int, scheduled_qty) AS scheduled_qty
FROM OPENQUERY(PROD_AXS, '
SELECT { fn CONVERT ( scheduled_qty, SQL_INT ) } AS...

Looks like there's a need for CAST instead of CONVERT:
SELECT CONVERT(int, scheduled_qty) AS scheduled_qty
FROM OPENQUERY(PROD_AXS, '
SELECT CAST(scheduled_qty AS varchar(18)) AS scheduled_qty
FROM AXS.PUB.sols...

Progress OpenEdge documentation link for 11.3.3:

https://community.progress.com/community_groups/openedge_general/w/openedgegeneral/1107.openedge-11-3-product-documentation

Then you need some syntax for converting data types in the native SQL language of the source database.  See the attached,

You are very welcome!

Take a look here:  https://docs.microsoft.com/en-us/sql/reporting-services/report-design/create-a-document-map-report-builder-and-ssrs?view=sql-server-2017
   and here: https://www.mssqltips.com/sqlservertip/3504/sql-server-reporting-services-bookmarks-and-document-maps/

Also, if your procedure was not actually receiving that NULL parameter value, it could ONLY be because you didn't set up the dataset to use the parameter, hidden or otherwise.

If your report were not running when you failed to supply a value for a given parameter, then you would need to be sure that the parameter properties ALLOW a...