second day shipping is not working today

I went ahead and enabled SSA and AHT to comply with the new OTDR requirement. With that, I am now seeing customers purchase the faster shipping option 'Second Day'. The order was placed in the evening on Friday, and now on Saturday morning the shipment is late... I see no option in my shipping settings to disable this and I saw in another post someone said it is enabled automatically....

Since Amazon goes off of PDT, if an order is placed for Second Day (same day basically) at 1PM PDT, that is 4PM EST; my orders from the day before are already picked up and scanned in be USPS by then. Am I suppose to go back out and get that 1 single order done and scanned in?

I am considering on setting up several of my fbm items to ship Second Day Delivery (Fedex and UPS) instead of standard ground. I get decent rates for 2 Day shipping on certain packages that would fit well with some of my items. In some cases its cheaper to ship 2-Day than ground which at times I use anyway regardless of the ground shipping setting and gets there much sooner before the promised date.

I am starting to notice sellers are not only getting the buy box advantage by lower prices but Faster shipping and delivery options which this looks to start getting the buy box advatange in itself, and is casuing me an issue by losing a lot of sales.

My question is if I set my items to second day shipping by default (Not FBM Prime) am I Obligated to ship on Saturdays and Sundays and also does it requrie delivery on Saturdays and Sundays or just Monday - Friday Shipping and deliveries?

Example: Receive and Order on Thusday and requires delivery Saturday, or an order on Friday and required Sunday.

And one other requiment, If an order came in on a Thursday Night/Friday, would that deliverery require Monday because it is counting a weekend as Two Day, etc or would it require by Tuesday.

I understand Prime requires weekend shipping and deliveries for FBM in which I cannot offer that requirment.

It seems they are now requring FBM to compete with FBM weekend shipping and expect us to ship 7 days a week. Not every company works around the clock like they do.