Masking tool in blender 2.82a Sculpt mode not working

I am starting to work with Blender 2.82a sculpting and I wanted to use the Mask tool. My problem is, there is no sort of black color appearing on my model. So I cannot put the details I want on my model. But when I create a new sculpting document, the mask tool works very well. Is there any connection to my problem since I started my model with Multires modifier and then applying it? Please help me guys.

Yes. It looks like it is the problem.
In 2.79, blender preserves mask data when multires modifier is applied.
But it looks like it was lost in 2.8 series.

I did not found a bugreport about that.
Maybe there is a new limit that we have to deal with in 2.8.
Or maybe that just passed under radar of devs.

But here, in 2.82a or 2.90 alpha, mask data is just lost after applying modifier.