Batch processing pauses

Hello

I have a problem with my v3.6.0 PhpList installation. When I process a batch, the batch doesn’t fully get processed and I have to manually click on “stop processing” and then “resume processing” to finish all. Also, I get logged out in the middle sometimes depending on the size of the list (usually under 1,200 emails). Here is my config.php settings. Any help would be appreciated. Thnx, Sebastian
Message I get when processing is halted:

176 messages sent in 301.14 seconds (2103 msgs/hr)
Finished this run
Less than batch size were sent, so reloading imminently

define('MAX_PROCESS_MESSAGE', 3000);
define('MAILQUEUE_BATCH_SIZE', 200);
define('MAILQUEUE_BATCH_PERIOD', 300);
define('MAILQUEUE_THROTTLE', 1);
define('MAILQUEUE_AUTOTHROTTLE', 0);
define('USE_DOMAIN_THROTTLE', 1);
define('DOMAIN_BATCH_SIZE', 1);
define('DOMAIN_BATCH_PERIOD', 1);
define('DOMAIN_AUTO_THROTTLE', 0);
define('MAX_PROCESSQUEUE_TIME', 0);