Virus
I keep getting virus reminders coming up in my calendar app, should I be concerned
iPhone 11 Pro Max, iOS 14
If running iOS 13 or earlier versions, check: Settings - Passwords & Accounts - Accounts - Any rogue entries here? If so, delete the rogue account.
If running iOS 14, check: Settings - Calendar - Accounts - Any rogue entries here? If so, delete the rogue account.