Reimporting tiled landscape for world composition creates seams?


I am using world composition and tiled landscapes exported from Houdini in UE4. If I import a certain set of tiles to create the streaming levels for the first time I am not having any issues with seams. This tells me that the source heightmaps are not the issue.

However, as soon as I try to reimport the same tiled landscape onto a different initial landscape (using the exact same export settings in Houdini and UE4), there are visible seams. This happens independently of how different the height information is. As soon as a set of tiles is reimported, where the height does not match the initially imported tiles’ height, there are visible seams. I have attached pictures of how the seams look as well as my import & export settings for UE4 and Houdini.

I am assuming that UE4 is not completely overwriting the pre-existing height data but I have no prove or handle to investigate.

Does anyone know what the reason for this is and how I could possibly go about fixing it?

Thank you!