Never seen this since day one of MAX (3D Studio)....
Got some terrain meshes generated in Rhino then 3ds exported and imported into MAX8.
Meshes are not dense. Simple editable meshes. When I drag in an orthgraphic viewport (top, front, left) the meshes move in unison about 10-20 feet (the whole topo is about 3000x3000 feet).
They sort of lag behind the rest of the model draging along, then jump to where they probably should be....drift behind, snap, dript, snap, drift snap. If I stop they are stuck in their off location...it's not just a viewport thing. The objects are really moving.
I noticed for two reasons, the MAX grid gives me a stable reference as I drag and the meshes superimposed slide around over it.
Also, I have polylines dwg'd out of Rhino and brought into MAX to loft as road stripes (Rhino will not 3DS out polyines) and these do not drift. Buildings I imported in from AutoCAD and cars I merged from other max files are stable. ONLY the topo meshes drift. It's almost as if the have a position noise space warp on them. Totally weird!
I really noticed it when I was editing the fogline spline to better follow the edge of the road. I'd move a couple of vertices, drag the viewport to see and move some more when the vertices I just edited were not in the right place. I thought the vertices in the spline were drifting as I dragged, but then finally noticed the meshes I was guiding them to were bouncing around.