Upload make directory with wrong owner

In a new complex environment with multiple server we are experiencing the following problem, users that make an upload this month have wordpress creating the years and month uploads directory but these are with wrong user/group, even if the user that run the server is apache and users have their own root dir.

we have a structure like thie:

clusterfs/web01/docroot/username/blogname/www

the doc dir for the single domain is www, www and blogname have user/group specific for the username. All the parents directory /username and above) are root/root owner/group.

Looks like WP get the owner from the new dir not from the site document root but a level above… that’s strange. I browsed in the WP code to get where exactly it gets the owner and dir it takes for template… but i didn’t found it.

Maybe just changig username owers/grouo will help? we would like to aviod a try and test for the various blog we have no access…

Thanks a lot to all will help ??