Dropbox app on MyCloud EX2 Ultra - Selective Sync not available

Sorry if I’m posting in the wrong place.
I’m on Dropbox app on a MyCloudEX2Ultra. While selecting the “Selective Sync” option I get a blank window, no way to select my main folders (Public, WORKFLOW and STORAGE) io their subfolders.
Any help is welcome.

There are dedicated subforums for the My Cloud EX2 Ultra where users more familiar with that device may be able to assist.

OS3 firmware My Cloud EX2

OS5 firmware My Cloud EX Series

Tnx bro.