Recently had an issue where Windows 10 (version 1151, build 10586.713) would wake up again about 30 seconds after putting it to sleep.
Fortunately the command powercfg -lastwake will give you the process that is responsible.
In my case it seems that it was related to GoToMeeting. Checking online and this seems to be a more general issue
For me the workaround was easier – I just un-installed GTM until they get this sorted
