This sounds just like what was doing. When they did it under x-rays, still no leakage. The last I went for my fill it should have had about 5 cc but nothing was there. They decide the port might be leaking and I told them to replace it. After then replacement it was checked and it was leaking around the edge of port. They told me where it was leaking it could not have been detected. Now that it has been replaced everything is great.