WorksOS

Selecting an Elevation Filter as a Global Filter or as a Widget Filter will cause "Work Completed" Widgets to give 0 volume answers. 

The reason is on the Dashboard, Work Completed Widgets only perform Volumes calculations for a single surface (ie filter) not like the Map Page Work Completed calculation that can perform surface to surface (ie filter to filter) calculations.

If a user applies a 'Lowest' Elevation Filter on the Dashboard either as a Global or Widget Filter then you are asking from the Lowest Pass to the Lowest Pass for the same single surface which is the same pass and no volume difference hence 0 volume being given as an answer. If a user does not apply an Elevation Filter then by default the Work Completed Widgets on the Dashboard perform their calculations from the First Pass to Last Pass of the single surface which will result in a Volumes answer.

Note: You can still use an Elevation Filter for Work Remaining Widgets on the Dashboard as they compare the single surface (ie filter) to a Design. Ie Lowest Pass to a Design will result in a Volumes answer. Also using a Work Completed Calculation on the Map Page with two different Surfaces (ie Saved Filters) will which will also result in a Volumea answer.