ColorFlakes
Have you taken an example blank email and viewed the raw contents to see if it’s truly completely blank or maybe contains some sort of error or maybe it’s malformed and the content isn’t visible because of that?
And you’re positive there are zero logs in all relevant logs (general server logs, webserver error logs, PHP error logs, MySQL/MariaDB error logs, osTicket System Logs, Browser Console logs, etc.)? Like there is nothing about any timeouts or anything being logged?
Cheers.