404 only on domain/gitlab/


I added the settings to my already running apache VirtualHost conf.
So I am using:
Alias /gitlab /opt/gitlab/embedded/service/gitlab-rails/public
<Location /gitlab>
ProxyPassReverse http://domain/
<Directory /opt/gitlab/embedded/service/gitlab-rails/public>

Now everything works if I go to specific links, but when I try to open the default page https://domain/gitlab/ I get a 404 error.

Can someone please help me with that? Thanks!