When you try to use the "Update" button after adjusting/modifying an existing report which was created in previous DLP version, UI throws error: "Report type is not updatable for the existing report".
DLP 25.1
Reports saved previously are not yet in form available to use update.
Use "Save As" option and use alternate/temporary name of the existing report, which will allow it to be saved and used later. The source report can be deleted. Then you can adjust the name of the newly saved report back to the original name.
Then you are able to use Update button every time you modify/adjust report.