2001 Dakota 42RE Shift Problem/s

First off Hello Everyone and Thanks for welcoming me to your group. I have a 2001 Dakota 3.9 4 speed automatic w/od (42RE). Recently after the fluid is warm or up to pressure, it starts to shift funny. It starts with a hard downshift then from there 1-2 and 2-3 won't shift until I reach 3k rpms+. Sometimes it won't shift to 3rd unless I move the shifter to the 2nd gear position and then back to drive and then it will shift into 3rd gear. The strange thing is if I shut my truck off and restart it it goes away for awhile. By awhile I mean the next hard downshift. It could be the next day or the next 5 miles, no real pattern other than what I've described. I recently changed out the Speed sensor to no avail but the fluid looks pretty dirty so I'm heading out now to drop the pan. Any input would be appreciated! Thank you in advance!