Changes to timezone do not appear to be applied

[cgevans]

Changing the time zone in the Date & time page has no effect for me: the time shown in cosmic-settings does not change, the time on the panel does not change, and the system time zone does not change. Closing and reopening cosmic-settings results in the old time zone being listed again.

Time zone changes via timedatectl do work.

System information:

• Running git cosmic-settings from PR feat: add control for alerts volume/mute (fixes #1017) #1653 , but that should not be related; running it via a full compile and sysext of cosmic-epoch.
• Distribution is Fedora Cosmic Atomic, up to date, but Cosmic itself is as above.
• Potentially notable, as there are some bugs throughout Cosmic with it: I have a fingerprint sensor and pam/sudo uses it.
• System is a Framework 13 AMD HX 370.

[cgevans]

It does seem to be a permissions problem:

  ERROR  failed to set timezone, why: "org.freedesktop.DBus.Error.AccessDenied: Permission denied"
    at cosmic-settings/src/pages/time/date.rs:279 on main