I was having an issue with syncing events between my MacBook Pro and my LG G2. A calendar entry entered on my MBP would show up in the calendar on the G2, but not vice versa. I finally figured it out. The Calendar app on the G2 syncs to a Phone setting, magenta. You need to tap the Phone block in the save entry and you are then given your email account. When the calendar is switched from Phone to you gmail account, everything syncs both ways.