I have installed the layout-card add-on.
When I use one of the new custom dashboard layouts (horizontal, vertical, grid, masonry), they work perfectly well on my windows computer, but when I cast them to my google nest hub, they show as a white screen.
The standard layouts can be casted fine to the nest hub.
Same here.
I did find that this custom layout does work when you update your dashboard to one of the Layout-card styles while you are casting.
This is only a temporary solution as it will stop working when you stop casting (and restart it).