Realy strange issue. In the problematic share, i had a folder called "system" with backup of old /etc folders of two previous servers. I saved these folders as reference for some manualy installed services (asterisk...)
I have deleted this folder and now the saving takes aprox 10min, but complete successfuly.
In a working share, you can see in a ssh session how the owner, group and acl are aplied folder by folder.
With this folder in my share, none of the folders are modified. once removed, the folders are modified as expected.
I have no idea what is the problem with this folder.
This is a newly installed 3.3, but i installed over previous lvm volumes where i have deleted everything but the shares folders.