Office 365 Japan Support on 25 Apr 2019 10:31:30
After publishing a report to Power BI Service, changing the parameter of the report will also overwrite the parameter value of the report on Power BI Service side when republishing (overwriting) in Power BI Desktop.
If you want to specify multiple reference target data sources with parameters and want to separately specify the reference destination when creating a report in Power BI Desktop and when displaying a report in Power BI Service side, set each time in Power BI Service Will be needed.
For this reason, you need the option to lock the parameters in the Power BI Service side of the report.