Security Heartbeat Showing 0

On an XG 17.0.6 MR-6. I am showing 0 Connected for Security Heartbeat. It showed this on 2-3 previous releases as well. It was working at one point but hasn't for quite some time. I have tried clearing registration with Sophos Central and then re-joining it but that didn't work either. 

Anyone else having this issue?

 

Thank you!