Hi,M E8
Hello, thank you for your reply, I apologize for getting back to you now, we gathered information for this issue and we found that this is currently a known issue.
We are continuing to monitor and investigate this issue on my end, and Microsoft is still working on fixing it. The latest progress I've made in helping you with your inquiry is that it may be related to OneDrive, as BitLocker saves are related to OneDrive. We recommend that you go to OneDrive.com to confirm whether there is a OneDrive freezing issue. If it's frozen, you can try to unfreeze it again, you can visit the link below to unfreeze it: What does it mean when your OneDrive account is frozen? - Microsoft Support
If it doesn't work, we suggest you can go to the website provided to you before and click ask a question, to continue to ask questions so that the bitlocker team can continue to investigate further.
Thank you for your time and effort working on this issue.
Best wishes
Bobhe | Microsoft Community Support Specialist