reset switch port to default

"I have a FortiGate and multiple FortiSwitches managed through FortiLink from the FortiGate. The issue is with the last switch in the topology—Port 1 on the last switch was dedicated as a trunk for FortiLink. I replaced it with another trunk port, but I can't reset Port 1 to default; it remains in the same state as shown in the photo. How can I fix this?"