Hi Damien!
Thanks for reaching out to us. Let me help you with that issue.
I’ve just tried to reproduce that in my own local installation but I do get the email notification sent.
This can be related to a theme or plugin conflict, so to narrow the problem down please go through the steps provided in the testing for conflicts guide > https://theeventscalendar.com/knowledgebase/testing-for-conflicts/ and let us know what you find in the process.
Also, please enable WP_DEBUG and WP_DEBUG_LOG. This will create a debug.log file inside the /wp-content directory.
After that, try reproducing the issue a few times, so that in case there is an error, it will be saved into the debug.log file. Please share that log file with us so we can see if any problem from there.
Thanks,
Victor