April 21, 2026, 8:23pm 1

Check Thunderbolt status

Install bolt if not present: sudo pacman -S bolt

Run boltctl list and boltctl enroll for the dock if it’s in “user” security mode.

Check: cat /sys/bus/thunderbolt/devices/domain0/security (should ideally be “user” or “secure”)

PCI rescan for USB/peripheral detection (often fixes USB devices on docks while displays work)

echo 1 | sudo tee /sys/bus/pci/rescan

Check for dock/laptop firmware updates via fwupd (sudo fwupdmgr update — connect dock first if possible)

Logs to collect (very helpful for diagnosis):

• journalctl -b -p err (after an incident)

• dmesg | grep -i thunderbolt or dmesg | grep -i usb

• lspci -k | grep -i thunderbolt

• lsusb -t (to see if peripherals appear on the bus)

Since direct HDMI also flakes, test with xrandr or KDE/GNOME display settings. Could be related to the iGPU driver (Intel on ROG Flow Z13)

Workarounds:

• Boot without the dock connected, then plug it in.

• For USB flakiness: Some docks need a power cycle or specific udev rules (see Arch Wiki Thunderbolt page).

  Thunderbolt - ArchWiki

• BIOS: Ensure Thunderbolt is enabled and security isn’t overly restrictive (look for “Thunderbolt Security” or “PCIe passthrough”).