Denver the city and county is a fraction of the Denver your buyers mean
The platform will happily sell you a municipality when your market runs from Boulder County to Castle Rock.
Denver is consolidated as a single city and county, so the city geo target in your account is a much smaller footprint than the market your brokers cover. Aurora, Lakewood, Arvada, Westminster, Thornton, Centennial, Littleton, Englewood, Broomfield and everything in Douglas County sit outside it.
Build geography deliberately instead. County level targets, or drawn polygons around the corridors you actually work, give you spend you can read. A radius drawn around a Cherry Creek office pushes budget west into the foothills where there is very little to lease.
Set location options to include people searching about your area, not only people physically in it. A corporate real estate manager in another state researching an expansion is one of the most valuable searchers you will see, and presence only targeting removes them.
Report by county from day one. Spend that looks fine at the account level often turns out to be one strong corridor carrying three weak ones.