Dataset permissions do not apply recursively

Hi, I have a dataset with posix permissions (no ACL).

I initially had permissions set to “office/office” as owner user and group with read/write/execute, read/execute, read/execute.

Later, I wanted to change these permissions to give the “office” group write permissions as well. In other words to have “office/office” with read/write/execute, read/write/execute and read/execute.

I used the gui to make the necessary changes, but I noticed that while this works for new files and folders, does not work for existing files and folders.

I am sure I used the “recursively” option. I also tried to re apply the permissions I want, but the process stops after a few seconds and nothing is changed.

The dataset is about 400GB with many thousands of small files. It is impossible changing permissions recursively to take only a few seconds.

Any suggestions?