HP Thunderbolt Dock inconsistent charging behaviour

[ftsartek]

I recently picked up a Thunderbolt 4 G6 Ultra 280w dock. So far, Thunderbolt/USB-C connections work as expected. However, on some devices the charging doesn't work properly.

On an Elitebook 640 G10, docking and charging both work exactly as expected.

On a Probook 445 G11, docking works as expected. Charging usually works, but the laptop doesn't always register that it's charging and will intermittently discharge.

On a ThinkPad P14s G1, docking works and charging works.

On a Lenovo Legion Pro 7 Gen 10, docking works (either via USB-C or Thunderbolt) but charging does not work at all.

On a Lenovo Legion 7 Gen 9, docking works via Thunderbolt, but charging does not work at all.

All of these devices support USB-C power delivery (the two Legions both support 100w PD charging: https://psref.lenovo.com/Product/Legion/Legion_Pro_7_16IAX10H and https://psref.lenovo.com/Product/Legion/Legion_7_16IRX9) - on other docks with USB-C PD charging works on all five laptops.

I can provide diagnostics that'll help, but it looks like neither Legion is negotiating power delivery at all.

Wondering if anyone here's able to provide some insight into why this might be, since the issue is specific to this dock and not to those laptops.

[banhien]

@ftsartek 

The main point: NOT all USB-C ports are the same that why we won't be able to use ONE DOCK FIT ALL. You have to check the compatible list then make decision which ones are IN or OUT. Please check

            https://www.hp.com/us-en/shop/pdp/hp-thunderbolt-4-ultra-280w-g6-dock#techSpecs

Regards.