We would need more information to determine what is going on. Create a SNMP walk for this F5 device and collect fresh diagnostics. Then please create a support ticket and attach those information's to it.
Here it is !
Case #408379 - "F5 BigIP - No hardware status"
The problem seems to be for the VE version of the F5. We updated one of our appliance model, and it works. Information seems to be in a different place for the virtual edition.