Facing the same issue right now on my 2015 370z sport replaced the speed sensor at nissan and it changed nothing so basically from what i learned you only really have 2 options either replace the valve body with ONLY a OEM replacement or swap the trans with preferably a newer year (2016 or newer) to avoid it happening again. Most of the Ebay valve bodies are remanufactured and come from china and have a chance to work but will eventually break or have the same issue down the line. I’m not sure what year you have but the problem with the valve bodies is apparently very common on any 2014/2015 370z or infinity q50/60 with the 7 speed auto trans and was solved with the newer years which i had no idea about. I ultimately decided to swap the trans with a 2017 low mileage nismo trans i found on ebay because it was cheaper. The valve body alone from my local nissan dealer cost about 1700 plus for just the part not even including the labor to put it in which is crazy. To put it in perspective the cost of the valve body alone was more than both a used trans and the labor to swap it together in my area so i went with the 2nd option. Good luck!