USB-C DP alt-mode dead after BIOS update on FW13 Intel 13th Gen — reinstall, downgrade, and EC reset all fail (zero typec ports, ucsi_acpi never binds)

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System: Framework Laptop 13 (13th Gen Intel Core), Ubuntu 24.04.4 LTS, kernel 6.8.0-134-generic
Firmware history: updated System Firmware via fwupdmgr 0.0.3.9 → 0.0.3.17; issue began immediately after the update+reboot. Currently back on 0.0.3.9 (see below) and still broken.

Symptom: External monitor (LG ultrawide over USB-C) is no longer detected. DP alt-mode never negotiates. Worked reliably before the update; same cable/monitor/ports.

Sysfs signature every occurrence:

• /sys/class/typec/ — zero ports registered
• all /sys/class/drm/card1-DP-*/status — disconnected
• Severity varies: sometimes the monitor's built-in USB hub still enumerates in lsusb (plain USB fine, alt-mode dead); sometimes the port is completely dead (monitor absent from lsusb). One occurrence showed a partial handshake: monitor briefly woke/detected a signal for ~1 min, then slept with no image.

Everything tried, in order — none fixed it:

1. Warm reboot — no change.
2. Full power cycle (shutdown, unplug all power/USB-C, wait 90 s) — cleared it once, then failed to clear a later occurrence. Not reliable.
3. fwupdmgr reinstall of System Firmware at 0.0.3.17 (same-version reflash, the fix that worked for the AMD reporter in BIOS 3.16 broke external monitor (USB-C DisplayPort Alt Mode) and caused severe boot regression on FW13 AMD 7040 #96) — reflash confirmed applied, no change.
4. fwupdmgr downgrade to 0.0.3.9 (my own last-known-good version) — confirmed now running 0.0.3.9, no change.
5. EC RAM-state reset: framework_tool --reboot-ec reboot (the fix confirmed in fn lock functionality breaks after the 03.09→03.16 Laptop 13(AMD7040 series) mainboard firmware(BIOS) upgrade #93) — partial improvement only: the monitor's USB hub came back in lsusb (port had been fully dead before the reset), but still zero typec ports and all DP connectors still disconnected.

Additional kernel-side finding after the EC reset: ucsi_acpi, typec_ucsi, and typec modules are loaded and the ACPI device USBC000:00 exists on the platform bus, but the ucsi_acpi driver never binds to it — no device symlink under /sys/bus/platform/drivers/ucsi_acpi/, zero ucsi messages in the entire boot's kernel log, and the device's waiting_for_supplier is 0 (so not a deferred probe). The UCSI probe appears to fail silently or never run, which would explain the permanently empty /sys/class/typec/.

(Ignored as known red herrings: cros-usbpd-charger error -71 probe messages, and one boot's cros_ec_lpcs: bad packet checksum d8 — the latter matches the known cros_ec_lpc ACPI-mutex race, not EC corruption.)

Question: Since both fixes confirmed in #96 (reinstall, downgrade) and the EC reset from #93 all fail on this Intel 13th Gen board, is there any way to fully reset EC/PD state on 13th Gen (no RTC coin cell, and the framewiki mainboard-reset procedure for 12th/13th Gen is marked under construction)? Happy to provide logs / framework_tool output.