I have spent 1,5 hours trying to figure this out. It seems as unnecessary item and a well-hidden one. This is valid for OBIEE 12c as well.
You have upgraded your OBIEE 11g instance to OBIEE 126.96.36.199.0.
Now when you export reports to CSV format file, you do not get more than 65000 rows downloaded.
In earlier versions of OBIEE 11g, you could download more than 65000 rows.
In OBIEE 188.8.131.52.x or 184.108.40.206.x, there was no specific parameter to limit download to CSV format but in OBIEE 220.127.116.11, one can add DefaultRowsDisplayedInDownloadCSV parameter.
There is a need to add a parameter in instanceconfig.xml, called DefaultRowsDisplayedInDownloadCSV, with which you can control how many rows are downloaded to CSV format. By default, number of rows downloaded is 65000 rows.
The DefaultRowsDisplayedInDownloadCSV parameter needs to be added to instanceconfig.xml as it is not there in the standard one. Customer could add it in case they need to download more than 65000 rows.