I've had this issue in prior versions and from other posts it appears others are also having a problem with "disabled" interpolation and resulting meshes appearing to still be interpolated.
For what it's worth, the projects I have experienced this with include LiDAR data.
I am meshing a flat surface, using strict volumetric masks, Depth Maps + Laser scans. The resulting mesh edges of the flat surface are rounded off. This causes quite an inconvenience in the workflow for this project.
Version 2.1.0 build 17532