Did you check if the tension on the take-up spool might be too high? I've noticed a pattern in a lot of mechanical stuff I fix around the house, like old sewing machines or even a squeaky lawnmower, where after a good cleaning everything runs smooth but then a tiny bit of friction or a small adjustment throws off the last little step of the cycle. It's like the parts need a little break-in time to settle into their new rhythm after being all cleaned up and tightened down.