Short of greatly improved Linux BitLocker tools, I don't think we can do anything about this. lsblk is correctly detecting that a partition is BitLockered, so the installer logic is valid.
The screenshot Brian posted is helpful for understanding what's going on - to Windows the BitLocker partition is not actually encrypted, but it's still in BitLocker format and not something we can interact with in the way the installer needs.
Short of greatly improved Linux BitLocker tools, I don't think we can do anything about this. lsblk is correctly detecting that a partition is BitLockered, so the installer logic is valid.
The screenshot Brian posted is helpful for understanding what's going on - to Windows the BitLocker partition is not actually encrypted, but it's still in BitLocker format and not something we can interact with in the way the installer needs.
I recommend closing the issue as invalid.