The issue affects global dashboards, specifically the header of the Classic graph widget configured with:

Override host → Dashboard

When the item name configured in the widget is identical across all hosts, for example CPU utilization, the Classic graph header is displayed correctly.

However, if I select an item whose name contains host-specific information, such as a network interface alias, the graph header continues to display the item name configured in the widget instead of the name of the corresponding item belonging to the overridden host.

The graph itself and its legend are updated correctly: they display the data and the interface alias of the currently selected host. However, the graph header remains unchanged and continues to show the original interface alias, which can be misleading.

I have attached a video demonstrating the issue.