I'm 99% sure its pure coincidence because its based on very circumstantial evidence but humor me. If you hold your phone and the bars go down pretty reliably. Do this and report back. 1. Test that its still doing. 2. Go wash your hands real well with warm to hot water and plenty of soap. 3. Dry Hands on towel. 4. Test again. 5. Report back. Just interested to see what happens.