We have heard reports of the IBM Verse App not syncing automatically anymore when using it on the new Samsung Galaxy S8 phones.
Android in general has a Application doze mode that can make applications stop operating when not up on the screen. Samsung took it a step further with having battery savings settings of Off, Mid and Max. Mid and Max would also prevent IBM Verse (and other apps) to perform background operations while not in focus.
This is under Settings - Battery
FYI: In the below screenshot you can also see the battery savings icon in the notification bar next to the speaker indicating that power saving mode is turn on.