You receive an email notification with a subject similar to "The system detected that one or more templates were updated as a result of a change in the EasyApache 4 environment."
This occurs due to EasyApache 4 updates changing the default template, this means that custom templates may need to be updated in order to follow suit.
You will want to review the following directory to look for a custom template, usually called ea4_main.local or something similar.
You can then use the diff command to look for differences between the default template and the custom one you have in place.
diff /var/cpanel/templates/apache2_4/ea4_main.default /var/cpanel/templates/apache2_4/ea4_main.local
For more information on how to use the diff command, I would recommend the following resource.