SUMMARY:
This issue is classified as a defect. The impact is limited to dashboards defined with Microchart widget which grid is set as a selector. One workaround is suggested.
SYMPTOM:
Even with "Show option for all" is checked, the option to unselect selector element is unavailable in Microchart widget where the grid is set as a selector.

STEPS TO REPRODUCE:

CAUSE:
This is a known issue with Strategy Web 9.4.1. "Select all" was possible by clicking the column header with Strategy 9.2.x.
ACTION:
Contact Strategy Technical Support for an updated status of this issue.
WORKAROUND:
Use refresh button to bring all the element back in the target.

TO LEARN MORE: