Good morning,

I have a new 5570 that replaced a 5540. I have a WD19TB dock that worked as expected with the 5540 and works as expected with a Lenovo test laptop. On the 5570, the dock is not identified as a Thunderbolt device when I plug it in to either of the two ports on the left side of the laptop, that is to say that within the Thunderbolt Control Center, Approve Devices, Attached Devices, and Manage Approved Devices are all blank.

Thunderbolt is enabled in the BIOS. I have attempted to install the Thunderbolt driver listed for the 5570 but the installation fails, presumably because it doesn't detect a Thunderbolt device. The laptop is fully up to date in Dell Command Update and there are no warnings in Device Manager, however there is no Thunderbolt controller listed under System Devices. I don't know if that is normal or not if a Thunderbolt device is not attached and detected.. I am running Windows 11 22H2 that is also fully up to date. I have tried a Lenovo TB3 dock and it is also not detected by the 5570, so the problem is definitely the laptop since the Lenovo laptop detects both the WD19TB and the Lenovo dock as Thunderbolt devices.

Any idea what I'm missing here?