Nextcloud Keeps Logging Out Web Interface

ℹ️ Support
1

Nextcloud version (eg, 12.0.2): 17.0.2
Operating system and version (eg, Ubuntu 17.04): 18.04
Apache or nginx version (eg, Apache 2.4.25): 2.4.29
PHP version (eg, 7.1): 7.2

The issue you are facing:

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

The output of your Nextcloud log in Admin > Logging:

Warning	core	Login failed: 'c***r@***.com' (Remote IP: '192.168.15.102')

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

<?php
$CONFIG = array (
  'theme' => '',
  'instanceid' => '***',
  'passwordsalt' => '***',
  'secret' => '***',
  'trusted_domains' => 
  array (
    0 => 'www.***.com',
  ),
  'datadirectory' => '/var/www/***/nextcloud/data',
  'overwrite.cli.url' => 'https://www.***.com',
  'dbtype' => 'mysql',
  'version' => '17.0.2.1',
  'dbname' => 'nextcloud',
  'dbhost' => 'localhost',
  'dbtableprefix' => 'oc_',
  'dbuser' => '***',
  'dbpassword' => '***',
  'logtimezone' => 'UTC',
  'installed' => true,
  'ldapIgnoreNamingRules' => false,
  'appstore.experimental.enabled' => true,
  'maintenance' => false,
  'filelocking.enabled' => false,
  'memcache.locking' => '\\OC\\Memcache\\Redis',
  'redis' => 
  array (
    'host' => '/var/run/redis/redis.sock',
    'port' => 0,
    'timeout' => 0,
  ),
  'loglevel' => 2,
  'ldapProviderFactory' => '\\OCA\\User_LDAP\\LDAPProviderFactory',
  'updater.release.channel' => 'stable',
  'remember_login_cookie_lifetime' => 1296000,
  'session_keepalive' => true,
  'session_lifetime' => 86400,
  'user_backends' => 
  array (
    0 => 
    array (
      'class' => 'OC_User_IMAP',
      'arguments' => 
      array (
        0 => '127.0.0.1',
        1 => 143,
        2 => '',
        3 => 'c***.com',
      ),
    ),
  ),
  'updater.secret' => '***',
);

The output of your Apache/nginx/system log in /var/log/____:


apache.log:

[https://pastebin.com/jhAXNADf](https://pastebin.com/jhAXNADf)
nextcloud.log shows this, however. 

[https://pastebin.com/jhAXNADf](https://pastebin.com/jhAXNADf)

Keep in mind, this is about 5 minutes AFTER a SUCCESSFUL login. Furhter. tcpdump -i lo port 143 shows no activity, at the time of the attempted login. It’s like Nextcloud is not attempting to reach out to the server.