Starting with the release of Strategy ONE (March 2024), dossiers are also known as dashboards.
SYMPTOM
'Metric Names' are not removed from visualization editor after the dataset is deleted in Dossier in Strategy Web 10.10
STEPS TO REPRODUCE
Follow the steps below to reproduce the issue:
1. Create a new Dossier by import a dateset from an Excel file containing 2 metrics;
2. Create a bar chart visualization, drag two metrics in Vertical zone:

3. Delete the dataset, note that the 'Metric Names' still appears in visualization editor:

CAUSE
This is a known issue in Strategy Web 10.10
ACTION
This issue has been addressed in Strategy Web 10.11. Upgrade to this version to take advantage of this fix once it is released.