FortiAP-W2 models may experience bootup failure during automatic firmware and federated upgrade process if they are powered by a managed FortiSwitch's PoE port

Disable automatic firmware upgrades and the federated upgrade feature if you have FortiAP-W2 devices that are exclusively powered by a PoE port from a FortiGate or FortiSwitch.

The federated upgrade feature starts the upgrades of managed FortiSwitch and FortiAP devices start at approximately the same time. Some FortiAP-W2 devices take a longer time to upgrade than the FortiSwitch devices. When the FortiSwitch finishes upgrading, it reboots, and can disrupt the PoE power to the FortiAP devices. If a FortiAP device is still upgrading when the power is disrupted, it can cause the FortiAP device to experience a bootup failure.

Both automatic firmware upgrade and manually triggering federated upgrade can cause this issue.

For more information about federated upgrade and automatic firmware upgrades, see Upgrading all device firmware by following the upgrade path (federated update) and Enabling automatic firmware updates.

To disable automatic upgrade:

config system fortiguard
    set auto-firmware-upgrade disable
end