windows calendar

win10, version 1803 (OS build 17134.523)- I mistakenly turned off my calendar notifications and I cant turn it on or uninstall to re install.  went through all of the setting in including reset. Got in a chat with MS support and they tried. they did a system restore and it still doesn't work. Steps: settings,system,notification and actions, calendar(via calendar), last step greyed out,cannot switch from off to on. Went through  all the setting in the calendar app and there is nothing about notifications.  It is linked with "mail" that must be in some bundle, maybe essentials. How can I resolve this problem? Hope i directed this question properly. Thanks.