If you have the chipped key IN YOUR POCKET, the valet key will start the carand it will run.
If you do not have the chipped key on your person, the car will not run.
So perhaps you were carrying the chipped key, and starting the car with the valet key.
Now, you left the chipped key off your person. And the car is doingwhat it always did check for the presence of the chip. not finding it. no start.
Just my 2 cents.
The chip does not have to be at the ignition switch, it just has to be in the area.