2008 nissan alitma 2.5 automatic

Hello my 2008 nissan alitma I installed a transmission
works perfect.  But here is my issue, you start the car out in
any gear will not engage. Fooled around with noticed that
after starting let idle for 45 seconds can hear a click then
you have any gear you want and drives perfect.  As long as
you let it run after starting it takes any gear perfect but as
soon as you turn the car off and come back to start it goes
Dee to the 45 second idle deal then off to go no problems
trans shifts flawless 0 slipping could not ask for a better
running car except on each and every start up . You sit a let
it idle until you hear the click tee hen you off to the races.
Never seen anything like this.