I thought I'd give people a heads-up about this issue. Placing it here may help get the bug resolved quickly. BUG-000090716
The download a filtered spreadsheet feature of Open Data Portal has a major bug. Once a filtered spreadsheet has been requested, all subsequent filtered spreadsheet requests return the same dataset regardless of the user making the request and the type of filter. This causes serious distrust in our ability to provide valuable services to our user community. This bug needs to be fixed ASAP. We don't have the luxury of waiting until the next Open Data Portal release.