I spent days trying to figure this out with my Note 4. I mean I tried everything I could think of. I finally resorted to googling it.... to NO avail... So I am posting right now to help other people with similar issues with both note 4 and other devices. Ive used this to fix issues with both the S5 and S6. Its simple really delete all apps that you don't use regularly. Apps are causing background issues in the current version of marshmallow. If updating all your apps doesn't work simply delete things you don't use. Test and see if that resolved it and then continue deleting. It might be just one app. I wish to compile a list of apps that are causing issues. As of right now I can say for my phone it was issues with a game I had called "that level again" I believe. If I find other apps causing issues ill add them here. Hopefully other people help out as well so its easier for others to narrow down what to delete.