UDT Device Tracker Unknown Vendor

Trying to understand why approximately 30% of the endpoints from the OUI Summary Report are coming up as Company <unknown>




Anyone know why this occurs or how to fix it? I believe normally the company is calculated based on the detected vendor portion of the MAC address.

Is there a way to determine which ports are coming up as company unknown so I can see if there are any similarities etc? 

I'm fairly new to using the Device Tracker and appreciate any assistance.


Thank you!