Since Zabbix 8.0.0rc1, dashboard widgets with Show header disabled still display a thin strip at the top of the widget.

This was not visually present in Zabbix 7.0.31.

The strip appears to correspond to the collapsed widget header area.

The strip is visually throwing of dashboards that use coloured background tiles to visually represent states. Headers should be entirely gone in these cases.

Steps to reproduce

1. Add an Item value widget to a dashboard.

1. Disable Show header.

1. Save/apply the widget.

Result

A thin strip of the widget header remains visible at the top.

Expected result

When Show header is disabled, no part of the widget header should be visible.

Affected version: 8.0.0rc1
Previously working: 7.0.31

See attached screenshot for an example.