Time Zone erroneously changes to "Pacific/Kiritimati"

When installing Ubuntu Kylin 18.04 LTS, I selected Los Angeles as my time zone. Once it was installed, I checked the Time and Date settings and it had reverted to the last entry on the list, "Pacific/Kiritimati".

I can use timedatectl to manually change the time zone to "America/Los_Angeles", after which the correct time will display. However, if I check the Time and Date settings again, it reverts to "Pacific/Kiritimati".

I would have used the "America/Phoenix" time zone, but Phoenix does not use Daylight Savings, so the time will be off when Daylight Savings is not in effect for Los Angeles.