One of my objects doesn't appear in the exportation pdf file

Hi !

I have an object which doesn't show when I export my file. It's a white object with an inner glow and a mask. The object under it is red. It is here when I am working with illustrator on the file but doesn't show when I save it in pdf and open it. Why ? What can I do to make it appear ?

It's strange because right next to it I have the very same objects which are all showing correctly when I save the file in pdf.

First image : on illustrator, what I would like the image to look like

Second image : on acrobat reader, the white layer on top disappeared.

Thank you for your help,

Léa