Problem with pattern fill

A designer sent me a pdf file which I imported in Corel Draw.

The file has several objects one on top of another.

When I import the file in CorelDraw, one of those objects is not visible. It is there, but it's not visible. First I thought the reason for that is because of its Order, somehow it had gotten behind the page, but now I think that's not the case. I checked, and the object has Full color pattern fill. I think the pattern fill is the problem.

I succeeded in reproducing the problem. Here is the object, which is invisible in CorelDraw, but not in the pdf, along with its Object properties:

 

And here is how it would look like if it's filled with black:

 

How can I avoid this problem?