Yes it is possible to glaze a belt. Check the secondary spring. Might be shot. I replaced mine with a new Cat red/wht and all was well. Don't know what you have for a spring but sounds like it may need some attention. I am assuming the C to C distance is correct along with offset too?
C to C = center to center.
Yes, scrub the clutch faces as well to break up the glaze that can also build up on them. Scrubbie with hot water and grease cutting dish soap [rinse well with hot water] or 200 grit sandpaper.