I am frequently recieving calendar reminders that I have not put in my calendar. NO one has access to my phone except me. I've recieved 3 so far this week.
@moon17 You are not forced to use Samsung Calendar. If you want to use Google Calendar use it. I use an app called aCalendar+ because I like the additional features.
For the shared calendar, have you tried going to the hamburger (3 line) menu in upper left and tried to remove that calendar?
OR going to the hamburger (3 line) menu in upper left, click the gear icon, click Manage calendars and tried to disable that calendar?
