Mysterious deactivation of apps

Nextcloud version (eg, 12.0.2): 16.0.4
Operating system and version (eg, Ubuntu 17.04): Ubuntu Server 18.04.1
Apache or nginx version (eg, Apache 2.4.25): Apache 2.4.29
PHP version (eg, 7.1): 7.2.19

The issue you are facing:
Yesterday I did an update from 16.0.3 to 16.0.4. After the update, everything worked normally. I used Phonetrack still around 2030h.
When I logged into NC this morning, several apps were disabled. If memory serves:
Calendar, Collabora Online, Everyone group, Flow upload, GPXPod, Phonetrack and Weather.
I re-enabled them and as of yet they work normally.
Note: The instance is accessible from the internet. I am, however, the only admin user and I use a strong password as well as 2FA.

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

Steps to replicate it:
Unknown

The output of your Nextcloud log in Admin > Logging:

No related output. Last log entry is 
Info	updater	\OC\Updater::resetLogLevel: Reset log level to Fatal(4)	
a day ago

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

<?php
$CONFIG = array (
  'instanceid' => '**********',
  'passwordsalt' => '**********',
  'secret' => '**********',
  'trusted_domains' => 
  array (
    0 => 'cloud.gofferje.net',
  ),
  'datadirectory' => '/var/www/cloud/data',
  'overwrite.cli.url' => 'https://cloud.gofferje.net',
  'htaccess.RewriteBase' => '/',
  'dbtype' => 'mysql',
  'version' => '16.0.4.1',
  'dbname' => 'owncloud',
  'dbhost' => 'nostromo',
  'dbtableprefix' => 'oc_',
  'dbuser' => '**********',
  'dbpassword' => '**********',
  'installed' => true,
  'theme' => '',
  'maintenance' => false,
  'asset-pipeline.enabled' => false,
  'loglevel' => 4,
  'trashbin_retention_obligation' => 'auto',
  'defaultapp' => 'files',
  'mail_from_address' => 'webmaster',
  'mail_smtpmode' => 'smtp',
  'mail_smtpauthtype' => 'LOGIN',
  'mail_domain' => 'gofferje.net',
  'ldapIgnoreNamingRules' => false,
  'ldapProviderFactory' => '\\OCA\\User_LDAP\\LDAPProviderFactory',
  'memcache.locking' => '\\OC\\Memcache\\Redis',
  'memcache.local' => '\\OC\\Memcache\\Redis',
  'redis' => 
  array (
    'host' => 'localhost',
    'port' => 6379,
  ),
  'mail_smtpsecure' => 'tls',
  'mail_smtphost' => '**********',
  'mail_smtpport' => '**********',
  'mysql.utf8mb4' => true,
  'updater.release.channel' => 'production',
  'app_install_overwrite' => 
  array (
    0 => 'files_downloadactivity',
  ),
  'updater.secret' => '**********',
  'twofactor_enforced' => 'true',
  'twofactor_enforced_groups' => 
  array (
    0 => 'admin',
  ),
  'twofactor_enforced_excluded_groups' => 
  array (
  ),
);

Hi,

we have a similar issue with the disabling of “Collabora Online” from time to time after the upgrade from NC15.x to the recent NC 16.x

Reenabling in the web interface works, but after some days out of nowhere it gets disabled again.