Not shifting when car is cold

Hi and thanks for using 2CarPros.com.

Based on your description, the first thing I would check is the fluid level. Automatic transmission fluid expands when it gets hot, which may be why it is working when it warms up. It is possible that a the problem is the result of a low level.

Let me know what you find as well as if the check engine light has come on.

Here is a link that describes different issues with transmissions. As you page down, you will find a section which describes no shift, soft shift. I added it thinking it may be helpful for you.

https://www.2carpros.com/articles/automatic-transmission-problems

Take care,
Joe