I've seen this problem discussed in many places and the responses always seem to center on Android settings. I had this problem and searched everywhere for a solution. I changed all the suggested settings and then figured it must be an app, but impossible to tell which one.. After lots of searching I found an app in the Samsung app store called "nice catch". It shows history of many Android actions including "screen wake up history" .. I instantly was able to find the offending app (next sms) and solve the problem!