SUMMARY
When I mount my TrueNAS server's pool directory using sshfs, Dolphin thinks I can write into it (right-click shows the "create new file" option), but actually can't (gives an error message). If per-directory view modes are enabled, Dolphin therefore tries to save a .directory file upon change, but fails and freezes. 
This seems to be the relevant part of code: https://invent.kde.org/system/dolphin/-/blob/master/src/views/viewproperties.cpp#L78


STEPS TO REPRODUCE
1. Have a TrueNAS instance or presumably any remote server where a directory is not writable (i.e., one cannot create a file in this very directory)
2. sshfs serveraddress:/mnt/mypool /path/to/mountpoint
3. Open /path/to/mountpoint in Dolphin
4. Change the view mode

OBSERVED RESULT
Dolphin freezes

EXPECTED RESULT
Dolphin silently handles the error (and saves the config elsewhere). 
Ideally, it also detects that the directory is not actually writable and hides menu options accordingly, although I am not sure who is to blame in this case.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Manjaro 22.1.0
KDE Plasma Version: 5.27.4
KDE Frameworks Version: 5.104.0
Qt Version: 5.15.8

ADDITIONAL INFORMATION
Related: https://bugs.kde.org/show_bug.cgi?id=214560