System information:
lovelace-state-switch: 1.9.5 (also tried master branch)
layout-card: 2.4.5
Core 2024.7.0b5
Supervisor 2024.06.2
Operating System 12.4
Frontend 20240627.0

Since I have updated to the latest beta version of HASS, the card is not shown correctly.

The card should look like this,

but is shown like this:

When I use the visual editor, surprisingly the card is shown correctly in the right preview panel.

By playing around with the panel settings, I have noticed this:
The standard setting for the panel is "raster" and is not working. When I change the setting to "horizontal", "vertical" or "grid" (provided by layout card), the card is working properly again.