The Over Ice mode requires a full cup of ice to function correctly. It brews at elevated temperature, then the ice cools it.
Fix: Fill your cup, travel mug, or carafe all the way to the top with ice cubes before you start the brew cycle.
If that didn't work: Ensure you've selected the Over Ice brew style. The brewer has dedicated buttons for Classic, Rich, and Over Ice. Select your size, then press the Over Ice button before starting.
Heads up: The brew volumes are approximate. Refer to the chart on page 10. If your cup overflows, you're likely using a cup smaller than the selected brew size.