WOW... I have a Ninja.. same problem, but I recently learned it IS the pods.
I've been buying Krazy Kuos for a while now. Like you, it worked great, then one day coffee grounds and steam and noises were all over. I found (after going through this twice with them now) that the pods are different. The ones that work have a dimple in the bottom of the cup amd the outside is slightly puffy with ridges all around it work with no problem, but the bad pods don't have either AND the label on top is different.
I order mine through Amazon but thought I should contact Krazy Kups just to be basically be told that isn't there problem amd I needed to speak with Amazon.
I got a refund but.... IT'S their coffee... isn't it?
I have pictures to show you what I mean about their differences, but unfortunately I don't see a means of being able to post them.
I Googled it amd it said that technology in the "lid" of the cups knows if it's an off brand.
Hummm... is Amazon making their own version??
Gale