Shared folder invisible in the Finder (Mac)

Hi there.
I got this ■■■■ problem since this afternoon : my girldfriend and I are using a shared folder on our MyCloud Mirror and she can’t see it in the Finder of the Mac, with her session… but I do with mine !
The odd stuff is that she can browse in this folder through the iPhone MyCloud app and also through the web browser, after connecting to the cloud.
Anyone having the same problem ?

Up for the post… anyone got any idea ?