Delll Precision 7770 Bios locked after firmware 1.34

After a firmware upgrade to 1.34, my 7770 is not able to enter bios anymore. I tried everything, it is still blocked. 

I am reporting a firmware-level issue on my Dell Precision 7770 workstation that requires escalation to engineering support.

System details:
- Model: Dell Precision 7770
- CPU: Intel Core i9 (12th Gen)
- BIOS version: 1.34
- OS: Windows (boots and operates normally)
- Service Tag:

<To protect you, your private information was removed from public view. All private data was saved to your private Case. DELL-Admin>

Problem description:
After updating the system BIOS to version 1.34, the system boots normally into Windows, video output works correctly, and overall functionality appears intact. However, BIOS access is completely blocked.

Symptoms:

- F2 (BIOS Setup) and F12 (Boot Menu) do not work
- Windows “UEFI Firmware Settings” restart does not enter BIOS
- Ctrl + Esc BIOS recovery does not trigger recovery mode
- System POST completes and Windows loads every time
- This issue started only after the BIOS update
- Troubleshooting already performed:
- Disabled Windows Fast Startup
- Forced full cold shutdown (Shift + Shutdown)
- Power drain (AC disconnected, power button held)
- External devices disconnected
- Internal keyboard confirmed working
- Multiple boot attempts with correct timing
- BIOS recovery key sequence attempted
- BIOS downgrade via standard methods not possible due to lack of BIOS access

Important clarification:
This is not a thermal, performance, OS, or display issue.
The system is operational, but BIOS access appears to be blocked by a firmware / EC state following the BIOS update.

Request:
This appears to be a known firmware / EC lock condition on some Precision 7770 systems after BIOS 1.3x updates. I am requesting:

- Escalation to Level 2 / Engineering support
- An engineering or recovery BIOS / EC firmware
OR
- A documented service / manufacturing unlock procedure to restore BIOS access

I understand that such firmware or procedures are not public and are only available through engineering escalation.