We have a report with a Multivalue parameter. We use the WebForms ReportViewer control to allow the user to make a selection before running the report. We have noticed that, when certain combinations of selections are made, if the user selects out of the combobox and selects back into it, some of their selections are lost. It is always the same selections that get lost.
I have checked the datasource that the multivalue parameter is bound to and there are no duplicate IDs in the list of values.
Are there any known issues with the ReportViewer control and multivalue comboboxes that might explain why certain selections can get unselected?