Up until last weekend (600-mile road trip, 50% WV (HILLS!) 50% OH, with cruise set to 65MPH, long uphill climbs would result in the tranny first unlocking in 4th, then downshifting a few seconds later into 3rd, as one would expect. On this past trip, when pulling a long hill, the tranny would shift directly from 4th (locked up) to 3rd, with a very rough shift.
Yesterday, I took the car out on the interstate and was driving without the cruise control turned on. While pulling a long hill, I gave it more gas and it downshifted normally, i.E, unlocking first, then downshifting to 3rd a few seconds later.