transmission troubles

I have a 2008 Escape 2.3 4x4.

Sitting at a stoplight and went to drive forward, but nothing happened. Got it pushed to the side of the road and tried every gear including reverse, but it wouldn't move. It would just rev up like it was in neutral. A few minutes later I tried again and I was able to back up and go forward a few feet and then it quit again. I then towed the car home and tried it later in the evening. At that point, it shifted and drove just fine. I drove it around the block and it shifted through all the gears. I tried it again this morning and it is still shifting properly, but I did notice a slow engagement into drive. There is also a whining noise from the transmission if I rev it up. The car did have a P0722 code and U2023. Is it possible for the output speed sensor or a wiring issue to cause this or am I looking at internal problems? The fluid still looks red and doesn't have a burnt smell to it.

This may not be related, but for some reason my trip meter/odometer screen was filled with dashes when this was happening. Today it is showing mileage again.