Foliage will not snap to terrain after deleting landscape splines

So I painted foliage on my terrain with “paths” made with the landscape spline tool. I deleted some floating paths and now the terrain won’t snap down to the terrain. Is there a way to fix this? I tried the reapply brush, but without luck.
ps. still pretty new to UE4 (coming from Cryengine)

can anyone give an aswer to this?