I seem to have discovered what appears to be a bug in the PBI Service concerning the use of cross-report drillthrough pages.
I have provided links to two pbix files that mimic the manner in which my actual reports behave but can be used to reproduce the problem based around a simple data model containing three tables: Grandparent < Parent < Child
Report with Drillthrough - "Page 1" contains a simple chart displaying a count of Parents for each Grandparent; together with associated table. A hidden "Drillthrough" page is defined with a drillthrough value that is based on the Parent[Parent Key] column - this displays Child records for the selected parent. Note that the "Keep all filters" option is turned off.
Another Report - "Page 1" contains a slicer to allow selection of a Grandparent value plus a chart displaying a count of Child records for each Parent. An image is provided that links to a bookmark that takes the user to a hidden "Detail page" that displays the same chart together with a table displaying Parent records. This page contains a copy of the Grandparent slicer that is synchronised with the slicer from "Page 1" - as such, the two pages are kept in sync. In "File > Options and Settings > Options > Report settings", I have enabled the "Allow visuals in this report to use drillthrough targets from other reports" setting.
Both reports are deployed to the PBI Service.
Running "Report with Drillthrough" in isolation, the user is able the drillthrough option from the table in "Page 1" and everything works fine.
OK, let's get to the problem...
1) When "Another Report" is run for the first time, let's say that the user chooses to filter Grandparent records to just "GP3". The associated records are displayed in the chart below and likewise, when navigating to the hidden "Detail page" via the image bookmark, the correct records are displayed in the chart/table. Now, the drillthrough option is used from one of the parent records in the "Detail page" table - this takes the user through to the "Drillthrough" page in the first report and displays the correct information. To return back to the calling report, the user must use the browser back button. Again, the correct records (associated with GP3) are redisplayed.
2) Now, let's return back to "Page 1" in "Another Report" and filter with a different Grandparent value, e.g. GP2; and repeat the steps outlined in 1) above. Whilst the correct data (associated with GP2) is initially displayed in "Another Report"; at the point that the user uses the browser back button to return from the cross-report drillthrough, the data displayed in "Detail page" reverts back to what was initially queried in step 1), i.e. data associated with GP3.
You might naturally think that using the "Reset to default" option in both reports would fix the problem but, no, it seems that the PBI service continues to cache the original GP3 filter context that was used in step 1). There seems to be no way of clearing this first-time filter context other than removing/reinstalling the reports.
Hope that my long-winded explanation of this issue is understandable and that someone can take a look and can reproduce/confirm that this is an issue.
