Batch Send stops after 5 mins

After upgrading to 3.6.10 and using Chrome and/or Brave with no ad or script blockers, my batch send has changed somehow. After 2 batches, it seems to stall (the 5 min mention in the title is arbitrary as I have not timed it), whereby I either have to refresh the page or re-sign in and Process the Queue again to get it going. I am only sending 125 emails per Campaign, but what was once an automated process has become a babysitting process.

Any ideas on how to get it flowing on its own again, or what to check?
• It worked fine through 3.6.9.
• I am sending through the browser (vs cron),
• I have gone through config.php, but perhaps I missed a setting, or misunderstood one,
• I am using PHP version 7.2 and have tried PHP 8.0.x (not sure which subversion of 8 my web host is using). I have the option of 8.1.x also but have not tried.

Thanks in advance. :slight_smile:

@mjhedger Is there anything on the Event Log page?

Bear in mind that phplist will send for a maximum of one minute (more or less) so the batch size and throttle should be consistent with that.

Batch size = 50 and through the Event Viewer, my average time between messages sent is 8 seconds, which is fine.
No error messages are found in the Event Viewer.