exchange 2013 healthmailbox not found

I am getting a slew of ProbeResult errors on my exchange 2013 server.  I have 5 databases running and it appears about half of my healthmailboxes cannot be logged into by the system.

Here is an example of one of the messages I get when I run get-mailbox -monitoring|get-mailboxstatistics:

WARNING: The user hasn't logged on to mailbox <DOMAINNAME>/Microsoft Exchange System Objects/Monitoring Mailboxes/HealthMailboxXXXXXXXXXXXXXXXXXXXXX' so there is no data to return. After the user logs on, this warning will no longer appear.

I also get this error in the ProbeResult Event viewer that seems to correspond to this message because it uses the same healthmailbox id:

monitoring mailbox HealthMailboxxxxxxxxxxxxxxxxxxxxxxx@<domainname> not found!</

If I run get-mailbox -monitoring the healthmailbox listed in the above errors is listed and I can see this same mailbox in AD under the Microsoft Exchange System Objects -> Monitoring Mailboxes folder so I know the mailbox exists.

I have already deleted all the HealthMailboxes and let the system recreate them, I have also rebooted my exchange server but am still having these errors for only half of the mailboxes.

Would appreciate any suggestions as I am unable to find anything related to this on the web.