About VSS (Shadow Copy) with bit locker enquiry

I am using Windows Server 2008 R2
3 Hardisk drive set
C: 100 GB - System
D: 1000 GB (Bit locker is enabled) - Data
E: 500 GB - Backup

Due to I would like to change Shadow Copy "Storage copy" from D: to E:, but I found that no drive can be select in shadow copy setting
I have tried to disable the setting and remove all "shadow copies"

If I use C: / E: to make Shadow Copy, the rest drive can be select

Now I would like to confirm that Bit locker drive can use the VSS with another storage area? (E:)
If do, any setting need to apply? And how?

Also, I searched that it may due to HDD dependency problem (Some mount point may created across the HDD)
How can I check it?

Thank you!