Just to give you some context before I lay out the issues, our organisation has enabled the extension CIForms for users to submit feedback data as a feedback form. Composer updates are run on all folders within the extensions/ folder before the site is deployed. This MediaWiki site uses MySQL for its database. The composer.local.json file even contains the latest phpmailer version (^6.5) and a few other dependencies. The way I run composer is I download composer-2 in a shell script, self-update, update --no-dev -o, install --no-dev -o and then remove the composer instance. Every extension uses the REL1_39 package because this site's MediaWiki version is 1.39.2 and uses PhP 8.1. The site is even setup to send emails when users request accounts to the admin, and it works. It even sends back a temp password to the user to sign up, once the admin approves the user. So SMTP is setup properly as well.
Currently, when testing out the feedback form as admin, I fill out the form and hit submit. The page takes a long time to load and then times out with a "504 Error".
When I check the Special:CIFormsManage page, I can see that the form has been submitted. I'm able to view and download the PDF as well. But I'm not sure why the page times out when Submit is clicked. I've done a Network inspect, but Special:CIFormsSubmit just seems to be in a pending state before throwing a 504 Gateway Timeout Nginx error.
I've checked the Nginx logs and the error on Timeout is as follows:
[error] 35#35: *226301113 upstream timed out (110: Operation timed out) while reading response header from upstream, client: <Masked_IP_Address>, server: <Masked_DNS_Address>, request: "POST /index.php/Special:CIFormsSubmit HTTP/1.1".
Although the feedback form data seems to be present on the Special:CIFormsManage page and can be downloaded, an email doesn't seem to be sent to the admin. As stated above, emails for account requests work, so SMTP is configured correctly in LocalSettings.php and $wgEnableEmail = true as well as $wgEnableUserEmail = true. Even under the wfLoadExtension( 'CIForms' ) line, $wgCIFormsSenderEmail is set to the admin's email as well as $wgCIFormsEmailTo. Even PhPMailer is set to its latest version.
Not sure why the admin nor I receive emails on submission of these feedback forms.
Any help will do please! Thanks in advance!