Android Question Better knowlege about layout with variants

Theoretically B4A should choose the most suitable variant (see this post). The fact remains that you can create two layouts, rather than two variants, and load the most suitable one yourself, based on a global boolean variable whose value you set according to the size of the device detected.

The problem is how to choose the layouts for different devices ? This way, it was more difficult to maintain.

I do not really understand the logic of your layout variants.
One layout, landscape, for big screens, tablets. What do you expect when the screen is in portrait.
One layout, portrait, for small screens, phones. And what do you expect when the screen is in landscape.
You could use two layout files as already suggested, check the screen dimension with
DeviceSize = GetDeviceLayoutValues.ApproximateScreenSize
and load the corresponding layout file.
Or post a small project showing the problem.

Here, a screenshot of two variant.
and 4 photos of 2 devices (portrait and landscape)

By coding, I know how to fix landscape for tablet and portrait for phone. And I can choose different layout for each.
But it will be more difficult to maintain. Is it a way to choose a variant?

I write a small project

From your screenshots it seems that you have more than 2 variants, at least three.
Phone landscape is different from tablet landscape.

Small project.
I create 2 layout, each of them have 2 variant.
LsmallVariantFirst layout have a phone variant on top and a tablet variant under phone one
LBigVariantFirst layout have a tabletvariant on top and a phone variant under tablet

On phone in portrait:
even I load any layout the variant Phone portrait appear on screen.

On phone in landscape:
when i load LsmallVariantFirst layout, it show a phone variant.
when i load LBigVariantFirst layout, it show a tablet variant.

On tablet on any orientation
even I load any layout the variant Phone portrait appear on screen.

I make a layout with 4 variants
For phone: landscape and portrait
For tablet: landscape and portrait

I try phone variants on top
And I try tablet variants on top to

On any device they show only phone variants on any orientation.

Ok I upload another small project with a layout and 4 variants.

If I understand well how it work, I can use only a variant for phone or tablet by layout. I have to pay attention on size of view and text size when I create layout to fit all device.

I can choose portrait for phone and landscape for tablet by coding it.