ZBrushCentral

Masking with SelectRect always selects backface

Hello!

I’m trying to fibermesh a beard.
I have a beard sculpt, and now I would like to mask only the “front” of it so that the Fibermeshes only “grow” on the front of the beard sculpt.

I have activated backface masking, and I’m then using the SelectRect brush to mask everything.
I’m expecting that only the front of the sculpt is masked, but when I then rotate the sculpt, I can see that the “back” of it has also been masked.

How could I mask only the front of the sculpt?

Thank you very much!