I first discovered this issue when a user complained she could not access a file I created on an NFS4 share.
I don't see this issue if I use fish:// to access any directory, local or remote.
We are on fully updated KDE fedora 34 and 35 systems, and this has been a problem for quite awhile, through many Fedora updates, possibly as far back as fedora 18 (arbitrary number). Until now I've usually just run chmod -R g+w on the share on the file server or locally when it matters, then went about my business. I have put it off too long and so did a bit of investigation.
This happens every time on both Konqueror and Dolphin. It never happens in Konsole. Meaning that if I open Konsole and cd to /fs1/work (the nfs share), and create a file or directory, the permissions are set to 664 and 2775 (SGID is set for all directories) as expected, with a umask of 002 for all users. Note that the umask on both servers and clients are set to 002.
So only Dolphin and Konqueror ignore the umask=0002 setting, and only when not accessing a file system via fish. This happen on both remote NFS shares and locally.
Emmett