I have a Samsung Note 8 and the 5X has been working flawlessly until update 7.60 came out. Now the watch doesn't stay connected to the phone, syncing works but has to be manually after 3-4 attempts. I now have a smart watch that is dumb, no notifications, very annoying.
LG V20 on Android 7.0. Notifications have been errattic since the last update, especially text msgs. But I don't have seem to have bluetooth sync issues, just doesn't always send a notification to the phone