Groups are being deleted...maybe LDAP

We are running GitLab EE 10.3.3 omnibus. We have LDAP auth working against AD. I can log in, etc. However, I keep having groups I created in GitLab go missing after a period of time. The only one of the groups which does not get deleted is one which has a matching group name in AD.

When you are running EE and have the group_base set in gitlab.rb, do you always need to have matching groups in AD?

Thanks.