Fortiswith blocking MAC addresses with unidentified OUI

HI,

I have experienced a very interesting problem.

I had a network device that was working fine when connected to using a computer or when connected via the FortiGate, however, when connecting via the FortiSwitch it would not work and the FortiSwitch would not even learn the MAC address (The interface was showing up and STP was changed to forwarding state properly).

After long time of troubleshooting i found that the MAC address on that network device could not be found in any OUI database. The manufacture created a new Firmware that corrected the MAC address and i was able to then use it via the FortiSwitch.

I'm trying to understand why the FortiSwitch was blocking it and if there is a log or something i could've seen it getting blocked. I was unable to find any relevant documentation. I'm not using any special security (No NAC, 802.1x authentication etc)

Using fortiswitch 148f-f with firmware 7.6.0