Hello Adrian,
Thank you for posting question on Microsoft Windows Forum!
Based on your query of removing all BitLocker error. Well! This error is happening probably because Secure Boot has been turned off or altered in your computer's motherboard settings (BIOS/UEFI). BitLocker monitors specific security checks called PCRs. PCR 7 specifically watches your Secure Boot status. Because Secure Boot is currently disabled or reporting different security data ("Mismatched PCR: 7"), BitLocker thinks your system has been tampered with and locked the drive to protect your data.
Please be aware: Before making any changes. Making sure you have the 48-digit BitLocker Recovery Key.
Since the error explicitly states SECURE BOOT DISABLED, turning it back on clear the error. The suggestion here is to re-enable secure boot. Restart your computer and press the specific key during boot (usually Del, F2, F10, or Esc) to enter the BIOS/UEFI settings or check your computer's brand splash screen or manual for the exact key. Once inside the BIOS/UEFI menu, look for a tab named Security or Boot. Find the setting for Secure Boot and change it from Disabled to Enabled. If there is an option for "Secure Boot Mode", ensure it is set to Standard. Save your changes and exit (usually F10). The computer will reboot. If this was the only issue, Windows should load normally without asking for a recovery key.
Otherwise, After restarting, the system should return to the BitLocker recovery blue screen. Enter the 48-digit recovery key you have. If the key is correct, your computer should boot normally into Windows.
Hope the above information is helpful! If it is. Free feel to hit "Accepted" for benefitting others in community having the same issue too.