[Bug] Tiled landscape add some space between edges

I create my own heightmap and divided in multiple png.
When i import it on Tiled landscape it create space on borders.

How can i fix it? Is there somethng i should do?

Should i fix it manually with the editor?

Strangely using smooth brush will solve the issue…
It’s very annoying since there a lot of tiles, but i can fix this bug.

In any cases is a bug.