Certificate status in 14.1.0

Dear all, I'm configuring a couple of new BigIP i7600 appliance running version 14.1.0.2 (Build 0.0.4). I'm importing certificates from an old VE appliance running 12.1.0. The import phase have been done correctly but I can see them in the SSL list with a grey rectangle in the status column. If I focus the mouse on it, it say "Status monitoring is not enabled or Status is not yet available". What status does it mean and how can I fix it?

Thank you in advance

Luca