DavDroid success to log but can't find CalDav or CardDav

Nextcloud version (eg, 12.0.2): 15.0.5.3
PHP version (eg, 7.1): 7.0.33

The issue you are facing:

I have Nextcloud 15 successfully installed on a mutual web server from OVH. Now I’m trying to sync my calendar and contacts with my Android phone. When I use the sync option in the Nextcloud mobile app and try to connect, I get an error telling me that it can’t access any CardDAV or CalDAV service. My Nextcloud logs say nothing. If I try to connect with a wrong password the Nextcloud log file will give me a “Login failed” entry. But with the right credentials the logs say absolutely nothing.

Is this the first time you’ve seen this error? (Y/N):
Yes

The output of your Nextcloud log in Admin > Logging:

NOTHING (logs empty)

The output of your config.php file in /path/to/nextcloud (make sure you remove any identifiable information!):

<?php
$CONFIG = array (
  'instanceid' => 'XXX',
  'passwordsalt' => 'XXX',
  'secret' => 'XXX',
  'trusted_domains' => 
  array (
    0 => 'cloud.mydomain.com',
  ),
  'datadirectory' => '/home/myserver/www/nextcloud/data',
  'dbtype' => 'mysql',
  'version' => '15.0.5.3',
  'overwrite.cli.url' => 'http://cloud.mydomain.com',
  'dbname' => 'mydb',
  'dbhost' => 'mydb.mysql.db',
  'dbport' => '',
  'dbtableprefix' => 'oc_',
  'dbuser' => 'mydb',
  'dbpassword' => 'XXX',
  'installed' => true,
  'memcache.local' => '\\OC\\Memcache\\ArrayCache',
);

The DavDroid log fil : can be found here

Thanks in advance

Shouldn’t be DavDroid now be DAVx5?

I’m not use if this is the right place to address DAVx5 related issues. You should address DAVx5 related issues in the dedicated forum in which you find information about how to configure the app and in which the developers provide and support.