Mattermost config being overwritten by gitlab-ctl reconfigure

I posted in the install forum about an issue with my upgrade to 11, I’ve discovered the behavior causing it, and it’s different enough (and not really related to upgrading) that I think it warrants it’s own topic.

Simply put, when I run gitlab-ctl reconfigure, any changes I have made in the Mattermost GUI (or directly to /var/opt/gitlab/mattermost/config.json) are overwritten. These are not settings coming from /etc/gitlab/gitlab.rb, they are settings that are now commented out in that file.

Is there stuff stored in Postgres that Chef is pulling from for this?

If it matters, I have an older (maybe 2 years old) Omnibus install, running on Debian Stable, so it’s been migrated to new versions over time. However I don’t have a whole lot of custom configuration in place.