As of yesterday Dec 7th, users are unable to execute pagination reports in the Power BI service and receive an error saying parameter values have not been specified for optional (allow blank) paramet...
Seems not resolved - still exists in PBI Report Builder V 15.7.1704.1
Create blank report with 3 parameters; DateFrom, DateTo and nullable prameter from the query.
Report ask to select all parameters even only dates will be rendered only.