Did Windows 10 disable encryption without authorization?

Solution 1:

The problem was caused by the Intel(R) Rapid Storage Technology (RST) driver that got installed by automatic updates. This driver has a known incompatibility with self encrypted drives.

It appears that the SSD has never been decrypted, but Bitlocker was unable to read its status properly due to the Intel RST. Replacing the faulty driver fixed the issue: now Bitlocker detects again, a fully hardware encrypted drive.

How To: Remove the Intel RST driver

1. Create a system restore point in case something goes wrong;
2. in the Device Manager locate the IDE ATA/ATAPI controllers;
3. open the Intel(R) ___ SATA AHCI Controller;
4. go to the Driver tab;
5. click Update Driver...;
6. click Browse my computer for driver software;
7. click Let me pick from a list of device drivers on my computer;
8. select the Standard SATA AHCI Controller;
9. apply and reboot;
10. BitLocker should now resume and detect that the drive is hardware encrypted, you can check it with manage-bde -status.

Source: Uninstalling the Intel(R) Rapid Storage Technology driver

Note: If it doesn't work, check the link above. And if you are still stuck, you can try - at your own risk - to completely remove the Intel RST driver. On reboot Windows will be unable to detect a boot device, and you will have to enter your Bitlocker recovery key and attempt an automatic repair. It should work and you should then be able to boot to your system that will be running on the Standard SATA AHCI Controller.