We went on Wednesday and had Dexcom training with our CDE. She put on the first one, it failed yesterday afternoon. Called, Dexcom is replacing it, no issues. Put a new one on last night, followed same procedure as CDE did, it looked secure. It just failed. What are we doing wrong? My DS doesn't have oily skin, we are using all the preparation/precaution tips we have received, yet they are still failing. I'm open to any/all suggestions. I'm also wondering if I call Dexcom again if they're going to replace again so soon. Thanks!