@myefc: That's strange. If you open the Calendar app > Tap the 3 lines in the top left > Tap the cog in the top right of the pop up window, then scroll down to Alerts, are you able to change the Alert Style and Alert Settings? If not, scroll down to About Calendar > Tap the 'i' in the top right > Notifications > General Notifications > Show Notifications > On > Alert > Show as pop up > On > Sound > Assign a sound. Go back and do the same for Other Notifications, and let me know if this helps.
