[Bug] In Full Screen Mode, Secondary Menu Floating Over GANTT chart

[rickyweb]

Summary:
When clicking on the Fullscreen icon at the bottom right of the GANTT screen, the GANTT chart is maximized, but the GLPI secondary menu is not hidden, it keeps floating over the chart, at its fixed position.

Current workaround:
Every time when the full screen mode is used, for example to present the projects to the board of directors, use the browser to edit the inline-style as follows:
<div class="navbar navbar-expand-md navbar-light secondary-bar sticky-md-top shadow-sm" style="z-index:-99">