Landscape patche seems to be bugged when close to each others, especially if it is set to additive. Its look like a patch want to cull another one.
Also when it use a heightmap, it seems like the 0 now go way below the landscape’s 0. Is that intended?
Previously, a pure black image (value of 0) would just do nothing on the landscape if it is set to the landscape’s height but now it is really digging it.
Thanks for reporting. It’s a known isue that has been fixed last week and will make it into 5.6.
Cheers,
Jonathan
I am testing on 5.6 the full release and have the same behavior. were the fixes added to the release?
Experiencing similar issues in 5.6 full release on my end
Clicking Reinitialize Height will plop it back up but the second it moves or I do anything it reverts back to this.
If it can help, it seems to only affect additive stamps.
The behavior feels like the “zero encoding” set to 0 have some really weird values. Like if the zero in this world is the lowest part a landscape can generate.
So, I made a workaround in my tool but long story short I need to do -0.854 / Z scale of the stamps and set the zero encoding to that number.
Also the LandscapePatch.UseExternalTextureAlignementFix = 0 didn’t do anything in my case.
Thanks for reporting this. We are able to reproduce the issue and are looking into a fix!
Thank you! 
