Why do I keep getting coffee grounds when it brews?
why do the pods keep leaking grounds when brerwing
take a look at the puncture needle areas and make sure that bottom one is not clogged. That would cause all the pressure from the K-cup to go to the top. Step 2 on this guide although slightly different model, should help you with that.
It could be a couple of things. The top needle could be dull after many usages and it is pushing down the pod before the needle penetrates the top seal which causes the bottom needle to go too far in the bottom and cut into the built in filter in the cup. Also it could be defective pods. If you use recycle pods this over time will dull your needle. Hope this helps.