Secure Boot?
The software vulnerability abused by Lambertz is also known as bitpixie (CVE-2023-21563).
Microsoft has known about it since 2022 but never managed to effectively address the issue.

The CVE-2023-21563 flaw is a “BitLocker Security Feature Bypass Vulnerability,” Microsoft said.
The hack requires a one-time physical access to the target system, plus a working web connection connection.