Changes on filesystem are not recognized (owner problem)

I have a problem with the synchronization after changing or adding files by ssh or ftp. I know about the config.php-entry and it worked with an older nc version on my system. But because I am on a shared server and they changed the owner system, now there are problems. I think it’s because the owner of the nextcloud folders and files is no more www-data.

Is there a possibility to solve this?
I also cannot use “sudo” because of the shared server.

Thank you!