Re: New FortiSwitches not appearing as Managed FortiSwitch
Refreshing the web page cache sometimes corrects that display. If not:
Did you update the firmware to be the same on the new switches? Can you access them directly through CLI or the switch web interface?
Did the ports you connected the switches to have interfaces with lldp-profile default-auto-isl? If they are just the default lldp profile that doesn't support auto-isl.