Trying to get the c3x working on my 2022 Hyundai Ioniq 5 with HDA-2.

Hardware:
C3x (new)
Hyundai Q Harness

Shortly after beginning a drive, sometimes pretty immediately and sometimes after a few minutes, I will get an error on my dash: "Check Forward Safety System" and then shortly thereafter, another error: "Check Lane Change Assist function" and then sometimes, but not always, a third error: "Check Lane Following Assist (LFA) systerm." At this point the automated steering will stop working.

The errors are accompanied by a message on the c3x: "CAN Bus Disconnected: Likely Faulty Cable." If I reset the c3x or put it in dashcam mode, the dashboard errors immediately go away. If openpilot is enabled again, I may be able to use it for a few minutes, but eventually everything will error out again.

Troubleshooting steps I've tried:

• Disconnect and reconnect all cables, inspecting connections, and making sure of a tight fit.
• Reset the vehicle
• Long reset the c3x (leave unplugged for extended period of time)
• Tried a few different good quality usb-c and thunderbolt cables to connect c3x to wiring harness
• Re-flashed openpilot firmware and ran any pending updates
• Tried sunnypilot with specific car model selected
• Tried openpilot nightly-dev build
• Re-wired harness to K adapter (read that this worked for someone on Discord, but it made mine worse)

Here is a route where the error happened: 0e81b110424b0fc2/0000000e--be4dc2118e/0

I have a request in with support and am still waiting to hear back. I just want to make sure I've done everything I can on my end. If anyone else has any info or ideas, I'd appreciate it!

One last thing I noticed:

The harness is my car does not have the wire with the red X. The Hyundai info page says one missing wire is okay, but shows light green as optional and this one is bold green - so I'm not sure if this is an indication of something wrong. My harness doesn't actually match any of the Hyundai listed harnesses.