Loading the same level twice through Load Level Instance BP Node will cause issues with levels containing Landscape as they will end up with the same GUID and the underlying systems do not support that.
We need to assign a new GUID when loading in an instanced level.
1) Create a new level "A" and add a Landscape to it. Save.
2) Create a new level "B", and add TWO Level Instances to it. Set both of them to point at "A".
3) Notice the errors in the log about duplicate landscape GUIDs.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-94532 in the post.