Cannot establish federation share nor add trusted server

Nextcloud version: 23.0.0
Operating system and version: Unraid 6.9.2

I have setup two nextcloud instances, each on their own Unraid server, internal ip addresses 192.168.0.21:9443 and 192.168.0.22:10443.
I want these servers to trust each other, as a test case for setting federation on a remote (non-local) server.

Steps to replicate it:

  1. In Administrative Settings, Sharing: add the other nextcloud server
  2. In files, Share a folder using the user-account of the other nextcloud server

The output of your Nextcloud log in Admin > Logging:

  1. OCP\HintException: No server to federate with found
  2. Exception: Sharing Documents failed, could not find admin@192.168.0.22:10443, maybe the server is currently unreachable or uses a self-signed certificate.

The output of your config.php file in /path/to/nextcloud (make sure you remove any identifiable information!):
[php]
$CONFIG = array (
‘memcache.local’ => ‘\OC\Memcache\APCu’,
‘datadirectory’ => ‘/data’,
‘instanceid’ => ‘’,
‘passwordsalt’ => ‘’,
‘secret’ => ‘’,
‘trusted_domains’ =>
array (
0 => ‘192.168.0.21:9443’,
1 => ‘nextcloud.mydomain.com’,
2 => ‘192.168.0.22:10443’,
3 => ‘nextcloud2.mydomain.com’,
),
‘dbtype’ => ‘mysql’,
‘version’ => ‘23.0.0.10’,
‘overwrite.cli.url’ => ‘https://nextcloud.mydomain.com’,
‘overwriteprotocol’ => ‘https’,
‘allow_local_remote_servers’ => true,
‘dbname’ => ‘db_nextcloud’,
‘dbhost’ => ‘192.168.0.21:3306’,
‘dbport’ => ‘’,
‘dbtableprefix’ => ‘oc_’,
‘mysql.utf8mb4’ => true,
‘dbuser’ => ‘usr_nextcloud’,
‘dbpassword’ => ‘’,
‘installed’ => true,
);
[/php]

Please advise on what I am doing wrong.
Thanks in advance.