If the store has set a per-weekday Maximum Pickups limit for the delivery-by-date schedule, once that many pickup orders have already been placed for a given delivery date, Pickup locks out for everyone else that day and you're shown "All available pickups for this day are full. Try delivery." (and vice-versa: a Maximum Deliveries limit locks out Delivery with "All available deliveries for this day are full. Try Pickup."). If both caps are hit on the same day, neither method is available and you'll see "All available delivery methods for this day are full." This is an advanced, per-weekday value (7 numbers, one per day of the week) that only a Sprwt superadmin can set — it isn't exposed in the store's own Client Config screen, and only applies when the store's delivery is date-based.