I was going to suggest the solenoid and transducer but you've already changed them. Might not hurt to pull them out and check for trash in the screens on them though it seems unlikely.

My 99 used to refuse to shift out of 1st unless you flashed it thru neutral, especially when it was cold. It got progressively worse. I just put up with it as I seldom used the truck. Sold it to someone that had big plans for it and wasn't concerned about it needing the solenoid etc.

Kevin