The "Number of Logons" attribute is not replicated, however Enterprise Reporter is designed to check the value for the user on all DCs and then calculate the sum. If the value in the report it is possible that the number of logons on each DC for that user is "not set". Taken from https://msdn.microsoft.com/en-us/library/ms676845(v=vs.85).aspx
"A value of 0 indicates that the value is unknown."
Verify the value for the attribute for the target user on each DC in the domain. Also ensure that the latest version of Enterprise Reporter is installed.