SDelete on EFS encrypted folder displaying weird behavior, filling up drives when no clean drive parameter specified

Question

C:\Users\user>sdelete -p 3 -r -s C:\temp\ToDelete

SDelete v2.04 - Secure file delete
Copyright (C) 1999-2019 Mark Russinovich
Sysinternals - www.sysinternals.com

SDelete is set for 3 passes.
C:\temp\ToDelete\ForDeletion.txt...deleted.
Zeroing free space to securely delete compressed files: 0%
Could not determine disk cluster size:
The system cannot find the path specified.

Zeroing free space to securely delete compressed files: 0%
Could not determine disk cluster size:
The system cannot find the path specified.

Cleaning free space to securely delete compressed files: 11%

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Running Sdelete to delete an EFS encrypted folder on a VM environment leads to this weird behavior where it tries to clean free space.

Question: is that the normal behavior of SDelelete? I wouldn't want this to happen in production, where SDelete fills up the virtual drive and I have no control over it.

Do note that my input is sdelete -p 3 -r -s C:\temp\ToDelete

There's no parameter to clean the drive supplied in the command.

In contrast, running SDelete to delete a folder that's not EFS encrypted will have a normal behavior.

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C:\Users\user>sdelete -p 3 -r -s C:\temp\ToDelete

SDelete v2.04 - Secure file delete
Copyright (C) 1999-2019 Mark Russinovich
Sysinternals - www.sysinternals.com

SDelete is set for 3 passes.
C:\temp\ToDelete\ForDeletion.txt...deleted.
C:\temp\ToDelete\ForDeletion1.txt...deleted.

Files deleted: 2
Directories deleted: 1

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Any help/advice would be appreciated.