Okay, also locale → comma separator is for currency value. It should not affect your port number.
Try this:
Locate and open config.php (and check config_override.php) using a text editor.
Find the $sugar_config['valid_imap_ports'] array.
$sugar_config['valid_imap_ports'] = array (
0 => '143',
1 => '993',
2 => '995',
3 => '1143',
);
Save the file and clear your cache via Admin > Repair > Quick Repair and Rebuild.
Solution: Updating to 7.14.2 causes issues with any imap port longer than 3 digits - #5 by ezon
Because you are running Docker on MacOS, container network isolation may prevent SuiteCRM from routing directly to a service on your host or external network over port 1143.
Make sure your custom email container is actually exposing or forwarding 1143