After Zurich Upgrade Dashboard report dropdown not working properly

[Baskarank]

In my servicenow instance - incident dashboard report dropdown was not working that funtionality and stacked by dropdown priority is shown twice,while selecting any priority no changes is reflected in the dashboard shows same as previous.

But that dropdown are working fine report (sys_report)

[Renat Akhmedov]

Hi Baskarank, 

This behavior is expected, as starting from the Zurich release, classic dashboards and reports (Core UI components) have limited functionality and compatibility. ServiceNow is transitioning all analytics and reporting capabilities to Platform Analytics (formerly Performance Analytics).

Therefore, it is recommended to migrate all existing reports and dashboards to Platform Analytics. Once migrated, dropdown filters and interactive controls will function correctly under the new analytics framework.

Please take a look for the video, 

https://www.youtube.com/watch?v=OA2mWEIEhuI

Hope it will help, please also mark this answer as helpful if it really helped you in some way,

Best regards, 
Renat Akhmedov