DIAGNOSIS The silicone rubber stopper/flap inside the brew basket that's supposed to seal when you remove the carafe is either stuck open with coffee gunk or has become deformed from heat.
FIX Remove the brew basket. Look underneath—you'll see a small, soft silicone flap. Clean it meticulously with hot water and your finger to remove any hardened coffee residue. Work the flap back and forth to ensure it moves freely and springs back to a closed position.
IF THAT DIDN'T WORK The flap may have lost its elasticity. The entire brew basket assembly is a single, inexpensive part. You'll need to order a replacement brew basket (part # often just called "filter holder" or "funnel") for this specific model.
HEADS UP When using the pause feature, pull the carafe out straight and smoothly. A jerky motion can cause a splash that defeats the stopper. Also, don't leave it paused for more than 30 seconds, as coffee will continue to back up in the basket.