We have discovered that in our current shipping products we have a cold start issue below -30C (recycling power at that temp). Below is what I was able discover in EP53F8QI. Problem is not seen on all the products but is seen on a few (~5-6) that we know off.
This is a shipping product so it would be hard to make any changes to the design at this time.
So sorry to hear that, i will send to you an personal email so you can use that email loop for sharing any confidential documents.
I would like to check, if your design has a delay circuit for Enable signal as shown in the datasheet page 12, where this delay required if the devices will work at cold temp to maintain the power on sequencing requirement.
Also please probe PVIN, Enable and Vout signals and share teh scope waveform for start up and shutdown events.