More than likely you have a cut seal in the transmission or a valve body issue.
However, based on the fact that it still works using the manual valve and shifting to 1 or 2 then that shows the seals are most likely just fine.
So that leaves a valve in the valve body being stuck.
Below is all the info on the valve body and how to disassemble it. Basically we need to pull it out and either replace it or pull the valves out to find the one that is sticking.
Let me know if you have questions and we can go from there. Thanks
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Tuesday, April 6th, 2021 AT 7:44 PM