Mine does this too from time to time; the issue is that coffee grounds stay up in needles that dispenses water into the k cup. This is why I keep a sewing pin or sewing needle close to it and when this happens I use the needle to clear the water dispensing needle. When I do this I always run a 6oz cup of hot water and typically a ton of grounds will pour out clearing the water dispensing needle. Also to avoid this I’ve been getting into the habit of throwing out the used k cup immediately after making a coffee.