Sorry it took us a long time to get to you ,
I myself have just come online and found your question ,
First with transmission problems you need to hook up a diagnostic scan tool to the transmission management system and check for malfunction codes ,A normal code reader will not find transmission malfunction codes .you need a dealer level tool .
Replacing the transmission is one of the last things you do if its working with the man mode ,
A diagnostic scan will confirm what sensor or part is causing you this issue ,
In your case the input/output speed sensors can cause you this issue ,could be the sensors or the connection and wiring problem .
If all this shows and test good then the TCM /PCM could be the issue .
Check with your dealer as a program reflash could also be a issue that may need checking .
Find a good shop that has the needed scan tool to check for trans malfunction codes ..
Need any follow up help then please get back to me with the reply button, and not the poor or bad service.
This way i can get back to you or suggest another expert if needed.
If i do not get back to you then i may be off line, and when i get back online i will get back to you..
Your deposit does not pay me until the answer is rated in a positive way,
Not rating or a bad rating does not constitute a refund.
If you are not happy or you have sorted out your problem before the answer then please let me know with the reply button .
Kind regards Greg.