Thought I would contribute in case somebody has my bizarre challenges. I’m trying to find a dock that will allow me to plug both my new FW13 hx370 (USB4) and my work M2 MBP (TB4) into my Samsung 57" monitor with HDMI 2.1. The FW13 really didn’t like my Thinkpad Thunderbolt 3 dock and it couldn’t support the HDMI needs.
I’m trying the new Anker TB5 dock, partially because I love their stuff and partially for future proofing. It can’t drive the Samsung directly with it’s HDMI port, but I can make it work by daisychaining a Cable Matters USB-C → HDMI adapter. It works with both machines in USB4 mode with a USB4 cable, but it only works with the Mac with a TB3 cable and will not work with the FW13 at all with a TB3 cable, throwing this error in dmesg:
ucsi_acpi USBC000:00: unknown error 256
I’ve concluded the hx370 FW13 can’t fall back to TB3 at all. This wouldn’t be an issue but I have a funny problem where some of my devices don’t actually work in USB4 mode because I end up with a hub depth >5 due to the need to use the monitor KVM and some of my USB3 hubs running internal USB2 hubs (including the Anker dock).
Anyway, first world problems. In short, the Anker TB5 dock seems to work great with the FW13 in USB4 mode and gives you forward headroom if you get a new TB5 machine.