I'm using wordpress 5.11 and CiviCRM 5.8.2. I am trying to get a CiviEvent to send confirmation emails but when I select the confirmation emails, the session times-out for the user (error 504). The registration does go through, but no email is sent.
Some observations, turning off the confirmation email works. Registration completes and it goes to the completion page.
I can go into Find Participants, Edit their payment and send a confirmation email from there and it works.
I'm configured to use CiviSMTP as my email host. I have no issues sending out bulk emails or day to day processing emails like renewal notices.
I have checked the logs and there is nothing reported.
I found a similar post here that suggested modifying/adding session.saved_path=/my/temp/dir which I put in as displayed here. I'm not certain that is the correct format. As displayed it made no difference. The 504 Timeout is consistent and happens every time.
Any help would be greatly appreciated - this is a big event and it opens on Friday so I would really like to have this working by then. I don't really want to have to do manual confirmation emails!