Not sure I understand what you're asking. Did you replace your firewall model with a different model (for example from 100E to 100F) and just copied the configuration from the old device to the new one? If so, I'd set up the new box from scratch rather than copying the config as copying the config from one hardware model to another doesn't necessarily work. Also, if there is a firmware difference that will most likely cause issues too. If that doesn't solve the issue I'd raise a support ticket, and expect to run an HQIP test.
The Fortinet Security Fabric brings together the concepts of convergence and consolidation to provide comprehensive cybersecurity protection for all users, devices, and applications and across all network edges.