magento2 – Magento 2.3.6 All emails stopped working even though Magento says it’s being sent successfully

I’m running Magento 2.3.6 with PHP version 7.3 and recently my Magento emails have all stopped working. I’m able to run a PHP script from the server to send emails through the mail function and they’re being received, but inside Magento all emails have stopped working.

I’ve tried looking in the system.log and debug.log, but there are no references to any email errors because Magento fully believes that all emails are being sent correctly. My configurations are set correctly, Disable Emails is set to no, Async email sending is set to disable. All my orders say that confirmation email is sent. Magento thinks everything is fine, but I’m just not getting any emails.

I’ve also tried installing Mageplaza SMTP extension to bypass any Magento mailing and I’m able to successfully send a test email, but again all other emails do not work.

Hope anyone has ideas, thanks.