Second Day Shipping Order Came in Today But Requires To Be Shipped Out Today?

Anyone have any idea what gives? We do fulfilled by seller and make custom personalized handmade items. It’s currently 7pm EDT and the order came in 6 hours ago. Obviously we didn’t notice until now which is too late, but why would a second day shipping option require the item to be shipped out say day?

We have order processing time set at 3 days. Our items literally can’t be made and ready to ship out same day. But the order is saying it has to be shipped out by tonight 11:59pm PDT or we’ll face a late shipment penalty.

Any idea what we should do? I don’t see why the second day option is just ignoring our order processing time.