owncloud in openmediavault webserver not accessible

Hello everybody,
I have installed owncloud within the openmediavault webserver (/var/www/openmediavault/owncloud/)

I did not use the plugin but did so manually because I wanted to use the latest 6.0 version of owncloud.

This setup used to run fine, but since a couple of days, apps can no longer connect to owncloud (owncloud news android app, cloudii android app). Webinterface is still working fine.

I tried to debug via REST client. When I send Basic Authentication headers to the owncloud adress (https://myname.somedynamicdnsprovider.com/ownlcoud) I can see from the answer that openmediavault webinterface is answering the request.

So probably somehow the request which is supposedly aimed at the subfolder is redirected to the root folder.

Could this be solved by altering some configuration of the apache webserver or changing some parameters in the .htaccess file?

the .htaccess file residing in the owncloud subfolder contains the followin mod_redirect information:

RewriteEngine on
RewriteRule .* - [env=HTTP_AUTHORIZATION:%{HTTP:Authorization}]
RewriteRule ^.well-known/host-meta /public.php?service=host-meta [QSA,L]
RewriteRule ^.well-known/host-meta.json /public.php?service=host-meta-json [QSA,L]
RewriteRule ^.well-known/carddav /remote.php/carddav/ [R]
RewriteRule ^.well-known/caldav /remote.php/caldav/ [R]
RewriteRule ^apps/calendar/caldav.php remote.php/caldav/ [QSA,L]
RewriteRule ^apps/contacts/carddav.php remote.php/carddav/ [QSA,L]
RewriteRule ^apps/([^/])/(..(php))$ index.php?app=$1&getfile=$2 [QSA,L]
RewriteRule ^remote/(.*) remote.php [QSA,L]

I solved the problem but don't really understand why.

In case anyone is interested:

I created a file "owncloud" in the "/etc/apache2/sites-enabled" directory with the following content:

Alias /owncloud "/var/www/openmediavault/owncloud"
<Directory "/var/www/openmediavault/owncloud/">
   Options Indexes FollowSymLinks MultiViews
   AllowOverride All
   Order allow,deny
   allow from all
</Directory>

after restarting apache all is working as usual. Seems to me like the alias was missing but I don't really understand it. If anyone wants to explain this to me, I'd be glad