If your Thunderbolt 4 Slim Hub or Slim Hub Pro is not being detected, check the LED first, because it tells you exactly where the setup is failing. On the Thunderbolt 4 Slim Hub (ST-T4SHM and regional variants) the LED lights orange when the hub has power but no host connected, and turns green once your computer is connected to the Thunderbolt 4 host port.

How to fix detection problems with the Thunderbolt 4 Slim Hub

1. Connect the included power adapter from the hub's DC port directly to a wall outlet. The hub needs its own power supply, and the LED lights orange once it has power.
2. If the LED stays dark, reseat the power adapter at the DC port and try a different wall outlet.
3. Connect the included Thunderbolt 4 cable from the hub's Thunderbolt 4 host port, on the front of the hub, to a Thunderbolt or USB-C port on your computer. The LED turns green once the host device is connected.
4. Make sure you used the host port on the front and not one of the three downstream Thunderbolt 4 ports. Only the host port connects to your computer.
5. Use the included 28 inch Thunderbolt 4 cable, or another Thunderbolt rated cable. A charge-only USB-C cable will not carry data and the hub will not appear.
6. Try a different Thunderbolt or USB-C port on your computer.
7. Check whether the hub appears in System Information under USB on a Mac, or in Device Manager on Windows.
8. On a Mac, confirm you are running macOS 11 or higher, which is required when using the hub with Macs.
9. Unplug the Thunderbolt 4 cable, wait a few seconds, reconnect it, then restart your computer and test again.
10. Reduce the load while testing. The hub can support more than one external hard drive, but one drive at a time gives the best performance.
11. Check which port your accessory is in. The USB-A 3.2 Gen 2 port runs up to 10 Gbps and supplies about 10W, and it does not support charging or the Apple SuperDrive. Connect a SuperDrive directly to your computer instead. The three Thunderbolt 4 ports run up to 40 Gbps and supply up to 15W.
12. Check your laptop's charging needs against the hub. The Thunderbolt 4 Slim Hub provides up to 60W of Power Delivery through its host port and the Slim Hub Pro provides up to 96W, so a laptop that needs more will not charge properly.
13. Test the hub on a different computer to confirm whether the issue is the hub or the host device.