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.