Transportation set Promise Ship to a day of the week by carrier calendar without impacting Pick Date

We have a requirement to default the day of the week based on the carrier calendar. We also have Lead Days and Transit Days setup. We noticed the Promise Ship defaults to the correct day of the week but the Carrier Calendar also impacts the Scheduled Pick. If we have 2 days of Lead Days, the Scheduled Pick is 3 weeks prior to Promise Ship because the 2 is considered as 2 weeks or prep. We also have a DEPOT calendar setup for our shipping BP where that is M-F and we expected the result of Pick