I spot 2 things in your scene:
First, the normals are reveresed which should reverse the displacement. Displacement only "knows" where front and back are because of the object normals. Fix this first.
Second, the topology is bad. There is no sugarcoating this.Corona's displacement is very robust, contrary to some methods the competition uses, but it is not unbreakable, as you can see for yourself. Long triangles will cause problems. If possible, use retopology on the surface. Maybe even the quad-remesher alone will help already. If you need displacement, I do not see any way around that. Remember that some materials rely on working UVs, though. What material are you using?
Michael