Has anyone had issues with the fuel pressure not maintaining itself at WOT on a Cruze?

I'm currently at 17-18psi at sea level and at initial WOT the fuel pressure on the scanner reads 57.x-58 as commanded but then drops to 54-56 after a few seconds, and I'm seeing it lean out. I've fudged the IFR versus fuel pressure to counteract but...

Car is otherwise stock.