I don't believe that is the issue. You can see the bitmap is being piped into 'cw_preview' - a custom preview node, similar to 'base material' - so the issue could be in 'cw_preview'. However, the issue persists regardless of whether 'base material' or 'cw_preview' is used to render in the 3D View.
Moreover, everything is being piped directly from the source bitmap, so it doesn't make sense why the base color, roughness, and normal are all being set correctly by the parent size drop-down menu, but not displacement.
I assume it has to do with the fact that the displacement resolution is being set by the tessellation settings in the shader, and not by the height map itself(?)