Comment 17 for bug 2061981

As Nathan correctly suggest, this behaviour relates to a snapd 2.62 new ability introduced for the personal files interface, to create missing parent directories of write paths/files indicated in the plug declaration. Release notes: https://forum.snapcraft.io/t/the-snapd-roadmap/1973

isPlausibleHome() is an early check (does not result in termination itself) to determine if the calling user have access to its supposed home directory, as a basic way to verify that unintended user cannot exploit the mechanism.

In the reported case the personal-files interface connection results in a special type of mount entry
that instructs creation of missing parent directories between $HOME and $HOME/.local/share.

none $HOME/.local/share none x-snapd.kind=ensure-dir,x-snapd.must-exist-dir=$HOME 0 0

Because this entry exists (when the interface is connected), the result from isPlausibleHome() informs if directory creation within $HOME should be allowed or not. This is way disconnecting the interface would solve the problem.

(1) Please `stat /home/department/user_name`
(2) Does the "permission denied" result in any AppArmor denials?