Most all of the Uniden database/Home Patrol series scanners ship with a database that is months. if not years, out of date,That's also the case with Sentinel- when first installed, it's database is also probably out of date as well.
While the scanner's firmware might be current, it's still to your advantage to get Sentinel installed, then update it's database, Then, write the updated data to the scanner, as well as check for any needed firmware updates just in case your scanner had been gathering dust on a back shelf before being shipped to you.