E4OD is confused?

[Highgate]

1997 F350, 460 and an E4OD 4X4. I bought the truck a while back and the transmission was slipping, bad. I continued to beat it around the farm doing chores knowing full well that it was going to need addressed but now it’s developed a new twitch. It will go from first right into fourth gear at like 10 mph. And then continue to try to kick down just to shift back up. If I click the “O/D off” button it seems to stop all together, and I can click it back and it will function fine. Is this something else inside the transmission or do I need to look elsewhere? It shifts fine manually as well. Thanks for any input, -Zac