Massive FPS drops in editor when moving mouse over menu items on Linux

Navigating various dropdown menus in the Editor causes the FPS to drop down to around 25 or 10 in the Viewport on an empty project.

This does not reproduce on Windows with -vulkan

This issues was reported and tested in 4.22 (CL-5660361). This was reproduced in  4.21.2 (CL-4753647) and Main 4.23 (CL-6032622).

1. Open the UE4 Editor and create a Blank Template project
2. In the Viewport toggle the 'Show FPS' option (CTRL+SHIFT+H)
3. Move the mouse cursor over File, Edit, Window, and Help

Results:FPS drops to low/red numbers

Expected:FPS doesn't change