HELP with Mikro Tik CRS354-48P plus Fortigate LANs

Hello,

I have a fortigate device that has three LAN ports configured and these ports are connected to a micro tik switch. I want to divide the switch into three different networks from these Fortigate LANs, so that network A does not have access to the other networks, network B looks the same, and network C has access to network B. I configured VLANs, but it does not work correctly. Thank you very much for any help

remove that unit from the rack and buy 2 CRS328-24P+4S-RM. Get a $10 DAC cable and uplink them together.

The CRS354 has been broken for years at this point with no sign that Mikrotik intends to do anything about it.