AA18250: Thunderbolt 5 dock fails USB4 Code 10 (specs in post)

Posting this so other AA18250 owners can compare notes and so Dell can see this is a repeatable platform issue, not a peripheral problem.

THE SHORT VERSION

My new Alienware 18 Area-51 (AA18250) intermittently loses its Thunderbolt 5 dock and external monitor, usually around sleep/wake or reconnection. Sometimes only the monitor drops while the mouse keeps working. In deeper failures the mouse, dock USB devices, and monitor all die and Windows plays connect/disconnect sounds on a loop. Rebooting the laptop does not reliably fix it. Removing AC power from the dock for about 60 seconds sometimes does.

The same dock, cable, monitor, and peripherals work perfectly on a different, less powerful laptop. This points at the Alienware, not the accessories.

SETUP

- Alienware 18 Area-51 AA18250, board 0D469V rev A00, BIOS 2.4.1
- Intel Core Ultra 9 275HX, RTX 5090 Laptop GPU
- Windows 11 Home build 26200
- Anker Prime TB5 Docking Station A83B5 (firmware V1.0, reported current)
- Samsung Odyssey OLED G9 G91SD, 5120x1440 @ 144 Hz

WHAT THE LOGS SHOW (for Dell engineering)

Dell SupportAssist's own detailed diagnostic log recorded this failure set twice on July 7:
- USB4(TM) Host Router (Microsoft), PCI\VEN_8086&DEV_5781: ProblemCode 10 (device failed to start)
- PCI Express Downstream Switch Ports, PCI\VEN_8086&DEV_5780: ProblemCode 51 (waiting on dependent device)
- Immediately after, the SupportAssist summary wrote "Passed." The detailed log contradicts the summary, so please do not close this on a green ePSA/SupportAssist result.

Windows event logs over 30 days, same machine:
- 69x USB4 Event 2 (Connection Manager could not enumerate the dock-attached monitor) vs 150x Event 1 successes, so the path is intermittent, not dead
- 26x WHEA Event 17 corrected PCIe errors on root port VEN_8086&DEV_7ECA, the exact port feeding the TB5 chain, including a completion timeout
- 103x ACPI Event 13 embedded-controller timeouts and 144x ACPI Event 15 EC/OS sync warnings
- During failures, the Intel xHCI controller (DEV_5782) fails D0 power-state exit/entry, then the USB4 host goes Code 10 and downstream devices go Code 43/51

The failure also occurred with the monitor connected DIRECTLY to the laptop and the dock carrying accessories only, so this is not a display-tunnel-through-dock or monitor-settings issue.

THE FIRMWARE DETAIL I WANT DELL TO CONFIRM

The BIOS 2.4.1 package lists Intel Discrete Thunderbolt 5 firmware 0.1.61.3 with a target of 0.1.64.1, and Dell KB 000476502 acknowledges a BIOS 2.4.1 Thunderbolt firmware-management conflict on the AA16250/AA18250, with BIOS 2.6.0 listed as the planned correction. My symptoms are consistent with the TB5 controller still running the old NVM because 2.4.1 cannot manage it.

ALREADY TRIED (no permanent fix)

- BIOS 2.4.1 reflash with the authentic Dell package
- Current Intel graphics (32.0.101.8860), NVIDIA (32.0.16.1062), Windows USB4/xHCI (10.0.26100.8521) drivers
- Elevated Device Manager restarts of the USB4 router, USB4 host, and xHCI controller
- Dock firmware confirmed current in Anker Dock Manager

QUESTIONS FOR DELL

1. Can you confirm whether BIOS 2.6.0 will actually apply TB5 NVM 0.1.64.1 on the AA18250, and the release timing?
2. Is Dell engineering tracking this failure signature (DEV_5781 Code 10 + DEV_5780 Code 51 + EC timeouts after Modern Standby)?
3. Is there a way to verify or manually update the discrete TB5 NVM under BIOS 2.4.1?

OTHER AA18250 OWNERS

If you're seeing Thunderbolt/dock/monitor dropouts, please reply with your BIOS version, dock model, and whether a dock power-cycle recovers it. There are at least two other threads on this board with the same signature (PCIe upstream Code 10, TB display dead while the same gear works on other machines). The more documented cases, the faster this gets prioritized.