From 3 weeks I had the problem that some part of my google account doesn't sync (Contacts, Gmail and some others). After 3 weeks of headbanging, deleting cache, data, backup, factory reset and everything else, this morning i figure it out that Power saving mode (PSM) blocks the sync (I figure it out randomly.... thanks God....). That problem appeared when I upgraded to Android 6 (it started then) and 6.0.1 (I'm still having this problem). I'm using Samsung Galaxy S6 for 1 year. Before the update (on Android 5.x.x) I've used PSM constantly and never stopped it. Even though the sync process was stable and everything was fine, I was receiving messages, notifications and everything. So now I should turn off my PSM so I can get my email notifications on time....
Is there any chance that PSM and google sync works together? It's pretty dump for me.... honestly. Or if it's not possible, I will suggest to Google to make PSM and some important apps (like Gmail, Email and others that people use all the time) to make them to work together.
Thank you for your time!