Found the Solution: The Engine Upgrade from 4.21 to 4.27 made some differences i was not aware of. In the Landscape Master icalled several Material Functions for the Landscape Layers and some of them were World Aligned Triplanar. In all of those World Aligned Material Functions i had this Vector Parameter Called “Size_Close”
For some reason 4.27 does not like it if you have the same named vector parameter in Function if those functions get called into 1 Master. So what he did was Pick one of those “Size_Close” at a Random and take its numbers for all other “Size_Close” aswell which explains why it did not save the individual results as this problem kept happening after reloading the Map.
I Solved it now by giving each Vector Parameter a unique Name like “Size_Close_Beach_01” or “Size_Close_Rock_01” now its working perfectly fine again.
Shout out to Epic: Why would you change the behavior of how Parameters are handled??