Blade 15 Advanced (2019) RZ09-0288 - Secure Boot Violation "Invalid signature detected" after Windows 11 update

Hello,

I'm looking for help because I've exhausted almost every troubleshooting step without success.

Device information

• Model: Razer Blade 15 Advanced (2019)

• Model: RZ09-0288

• BIOS Version: 1.03

• Windows 11 Insider Preview 25H2 (Build 26200.8737)

Problem

After a recent Windows update, enabling Secure Boot prevents the laptop from booting.

The firmware immediately displays:

Secure Boot Violation

Invalid signature detected. Check Secure Boot Policy in Setup.

If I disable Secure Boot in the BIOS, Windows boots normally.

Unfortunately, I need Secure Boot enabled because games such as Valorant require it.

What I have already verified

• Windows installation is healthy (sfc /scannow found no integrity violations).

• Boot files have been recreated using bcdboot.

• System is running in UEFI mode.

• TPM is functioning correctly.

• PK, KEK, db and dbx Secure Boot variables are present.

• bootmgfw.efi has a valid Microsoft signature (verified with PowerShell).

• SecureBootRecovery.efi exists.

• I followed the official Razer Secure Boot recovery procedure.

When booting from the recovery USB, the recovery tool displays:

"The Secure Boot database already contains the Microsoft UEFI 2023 certificate..."

and then immediately reboots, so it never performs any repair.

Has anyone with a RZ09-0288 experienced the same issue?

Is there a newer BIOS, firmware update, or internal recovery procedure available for this model?

Any help would be greatly appreciated.

Thank you.