Many UserLogonFailure events - user name is correct but the password is wrong

Our Primary Domain Controller (PDC) shows many, many UserLogonFailure Events (4776) with the text: "user name is correct but the password is wrong" and also "Error Code: 0xc000006a Error: user name is correct but the password is wrong".  The AuthPackage is: MICROSOFT_AUTHENTICATION_PACKAGE_V1_0

I suspect somehow this is our O365 accounts using Azure as it is linked to our Domain Users.  However, I'm not sure.  Insertion and Detection IP's are both the PDC.  The Source Machine is the workstation.  Any ideas on how to resolve these?