I had the same problem with Windwos silently deciding to encrypt ALL my other disks, notably those containing ALL my personal files, ALL my backups, and other non-windows systems, including virtual disks for virtual machines.
I was never asked the permission to encrypt those drives: Windows started to encrypt ALL these disks in parallel (it would take many hours to complete, more probably several days as they were started all in parallel, with HUGE I/O amounts).
I could not interrupt this encryption. But then there was a Windows Update forcing the system to reboot with a time limit of 10 minutes.
There was NO way to interrupt the reboot.
After this reboot, ALL partly encrypoted drives became unmountable. The recovery keys were correctly backed up, but were still not usable: Bitlocker had already encrypted most metadata on these drives, but not all. There was NO current state saved on the encryption in progress.
When using the recovery keys (which were accepted): these volumes came back as "RAW partition": NTFS metadata was partly corrupted.
All recovery tools have failed. There may remain some unencypted data spread over the disk, but WITHOUT any of their metadata (notably file attributes, names, security ACLS, parent directory; allmost all directories hwoever were already encrypted (but were now pointing to incorrect positions on disk).
Forcing in Windows to use Biotlocker on ALL drives without permission is a MALWARE behavior.
Encrypting/decrypting multiple volumes in parallel is a SEVERE DEFECT, that should never be done: doing them one by one at least preserves other volumes containing backups.
Those volumes are NOT exclusive for use by the current instance of Windows 11 only. Those volumes are OUR data, not yours. Connecting or mounting a drive should NEVER instantly initiate their encryption (using an encyption system that is also VERY specific to the current instance of Windows and NOT compatible with other versions!)
So BITLOCKER has DESTROYED (and very fast) TERABYTES of personal data. And this is definitive, NOT recoverable at all.
BITLOCKER is completely unable to SAFELY suspend its encryption progress and resume it only later. IT will NOT suspend itself during an OS reboot. It will crash definitely if there's a Windows Update in the middle of the next reboot.
BITLOCKER IS A MALWARE !!! THIS IS A VERY CRITICAL BUG. Bitlocker does NOT help use prevent damages by malwares, BITLOCKER IS THE MALWARE itself, even worse than every ransomware seen (you can't even pay a ransom to Microsoft to recover).
There are other competiing disk encryption systems that are MUCH safer (and even FASTER, and that are stable and usable across multiple OSes). BITLOCKER is just a crap. TOO DANGEROUS to keep in Windows.