The left part of the page is under the mini menu.

[ManWan888]

if material-shall isMiniMode is true and isMenuOpen is false then left part of the page is under the mini menu

"base-shell": "^2.5.14",
"material-ui-shell": "^3.4.14",

In the file lib/container/Page/Page.js, it seems that the code does not handle isMiniMode is true and isMenuOpen false case.

/#PURE/_react["default"].createElement(_material.AppBar, {
position: isDesktop ? 'absolute' : undefined,
sx: {
width: isMenuOpen && isDesktop ? "calc(100% - " + width + "px)" : undefined,
zIndex: theme.zIndex['drawer'],
transition: theme.transitions.create(['width', 'margin'], {
easing: theme.transitions.easing.sharp,
duration: theme.transitions.duration.leavingScreen
}),
maxHeight: 64,
marginLeft: isRTL ? 0 : -12,
marginRight: isRTL ? 30 : 0
}

[ManWan888]

I have queried google on the issue. Gemini responses:

Based on the behavior of the Material Shell GNOME extension for Linux, if isMiniMode is true and isMenuOpen is false, the main part of the page is positioned to the right of the mini-menu. This creates the following visual layout:
A thin mini-menu: A narrow, vertical panel is displayed along the left edge of the screen.
The content area: The rest of the screen is used to display the currently selected workspace and its application windows, positioned to the right of the mini-menu.
How Material Shell manages window layout
Material Shell is a tiling window manager, which means it automatically organizes open application windows to fill the available space. Instead of overlapping, windows are placed side-by-side or stacked.
The status of isMiniMode and isMenuOpen affects the layout as follows:
isMiniMode: true: When the user enters "mini mode," the main left-side panel, which normally shows a full list of workspaces and application icons, is minimized into a thin strip.
isMenuOpen: false: This indicates that the user is not currently viewing the full, expanded menu.
Therefore, the main content area of the screen will only be obscured if isMenuOpen becomes true while in mini mode, causing the full menu to temporarily expand over the main work area. When it is false, the content area is simply shifted to accommodate the narrow menu strip.

If this is by design, the issue should be closed.