Hello Tim Andersen,
I am sorry for facing an issue with EP53F8.
I have sent you an personal message, so you can use it as a private channel to share any confidential documents.
Please help to provide EP53F8 schematic and layout for review.
Also please help to provide a startup and shutdown waveforms from any working board, so we can understand if there is any risk during that events.
Please probe PVIN, VOUT and Enable signal.