The Desktop help panel is appearing shorter than the expected 528px height.
1. Set a fixed height on the panel
Set on a class that includes height of the entire panel including header + footer (e.g., .oo-ui-window-frame) to be height:528px;
2. Set a max-height on the panel
In cases where the browser window is shorter than the height of the panel, the height of the panel should be shortened so that users can still access the help panel header actions, and be able to see the "Edit" tabs on the page.
Set the following max-height on the same class as item #1:
max-height: calc(100vh - 180px);