i have fgt 300d 5.2.11 with 5 FortiAP connected as local bridge with single SSID, my issue is that when users move between offices they dont get the closest FortiAP signal, am not that expert in wifi so am not sure is it an option i have to configure or its a bug in the system.
Some settings within the FortiAP Profiles menu in the GUI can influence this, you can set the radio power to Auto (helps with channel overlapping if you have a lot of APs) and AP Handoff (the AP will move a client once the signal reaches a certain signal strength (you can customize the signal strength setting when this handoff occurs in CLI, reference AP handoff in CLI help docs) from what I remember. Frequency handoff also pushes clients to the less used frequency to balance load (doesn't help with your exact issue but can help with congestion). Let me know if either helps.
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.