My landscape paint is cut off.

[qusrby]

My landscape is cropped.
In my Landscape Material, Layer Info has already been created.

[qusrby]

I found the cause of the problem and also found a solution.

Landscape layer blending issue with more than 3 layers.

You’re run out of texture memory. In you material, click on all the textures and change ‘sampler source’ from asset to ‘shared: wrap’. Vertex painting is for meshes not landscapes, so best to stick to a landscape material.