Have you seen this recent thread ? Difficulty in establishing a connection between 2 surfaces (shell) in Prepomax
Meshes don’t have to match for these constraints to work. They have a tolerance that you can change to make them identify nodes further away than the default value allows. Of course, it should still be a reasonable distance and it’s important to select master and slave surfaces properly (master should have a coarser mesh).
In the Geometry tab, you can select Geometry → CAD Part → Flip Face Normal. It will display the face normals using 2 colors. but not per node (this is before meshing, just to check the geometry). To do it on the mesh, you could use ParaView.
Maybe try meshing with the default mesher instead of Gmsh (add only the Meshing parameters object). If it doesn’t help, try using tie constraints instead of a single large compound.