Hi, thanks for the detailed comments. I initially planned to make a bigger level with jumping parts in it but there was no time for that in the end.
THe Landscape bug must somehow be related to the combination of blueprint brushes, manually painted landscape layers and the experimental water system (which is on its own landscape layer). The landscape is not a static mesh... But I never had problems like this with sculpted landscapes without layers...
I guess I created the cutscene as my last action before submitting cause i shortend the initial cutscene a bit(I think it is still quite long...