Our S4 has recently started to to something strange. When we assign it to clean our kitchen floor it will get to the end of the cleaning and instead of going back to the dock, it will just sit in one place going full blast on suction but not moving. I know this is common when it gets confused on thick carpet but our kitchen has sheet vinyl (linoleum type) floor. The only way to get it to stop this is to hit the home button on the top twice to force it to return to the dock. Any ideas on how to make it stop doing this?