Hi,
I noticed you said dual boot configuration on device, do you mean dual boot (Windows 10 & Windows Server 2019) on virtual machine?
Do you want to enable Bitlocker on bootable drive or data drive on Windows Server 2019? Does the issue occur when try to enable Bitlocker on OS drive or data drive?
I noticed your Windows Server 2019 installed on VMware. As Microsoft does not support the use of BitLocker on the bootable partition of a virtual hard disk. Please see the description below: (Resource: BitLocker support in a virtual machine (2036142))
So please check if it is available to use Bitlocker on data drive and feedback result to us.