It's not what it seems. According to Kensington, there is no master key for these locks. They work correctly, but the master key is not possible.
Kensington Microsaver Universal Computer Key Lock and Cable Security System 64162a for Desktops
9 Review
π Sturdy Combination Lock for Laptop and Notebook Computers: 6mm Thick Black Security Cable Included (6ft Long)
9 Review
Improve your iMac Security with the Kensington SafeDome Secure Lock (K64962US)
11 Review
Secure Your Laptop with the π Kensington K64638WW ClickSafe Keyed Twin Laptop Lock
12 Review
Apple AirPods Pro MagSafe RU Wireless Headphones, White
159 Review
Sennheiser PC 8 2 Cancelling Microphone
71 Review
Logitech HD Webcam C270: Crisp 720p Widescreen Video Calling & Recording (960-000694), Lightweight and Portable at 3.15 lb.
192 Review
Smartphone Samsung Galaxy A50 4/64 GB, 2 SIM, black
82 Review