How to mask each parts of subject in LR Mobile ?

I'm new for LR mobile. just subscription.

Last week, I use LR Mobile "Select Subject" in Masking feature and get separate mask of each part (such as teeth, eye, lip etc.) in masking result.

But today, when I use this feature, both iOS and Android (both .jpg and raw), I just get a one mask of the whole subject.

Now, so confuse.

What I do wrong in setting ? or

Is there this feature in LR mobile ?