iPhone Invite/Invitee Responses not Working

Hello!

In the past, I've submitted multiple tickets under my Apple ID to request that Apple fix the Calendar invite/invitee response feature. I joined the iPhone community back in late 2014 when I received my first iPhone. I learned that anytime you created an event via the iPhone Calendar and sent someone an invite to that event you would get notified if they had accepted or rejected that event. This would occur regardless of which email system they were using. I have always used my gmail email address as my iCloud Apple ID. And to be clear, I do not use gmail calendar, I use Apple Calendar and embedded in the Apple Calendar app is the option to use iCloud/iCloud Calendar as an option for your main calendar. Of course you would have calendars such as gmail, outlook, etc, if you synced those calendar in via the now 'Passwords and Accounts' section, but I do not have my gmail calendar synced. I do not have an @icloud or @me email address, I never have. But now it seems, I have not tried this yet myself, that you must have an iCloud email address in order to get notifications via iPhone that someone accepted or rejected your event. For me, it does not make sense to make that feature an exclusive iCloud email address feature. I also do not want to create a new email address to get access to this one feature that used to be available for everyone.

I want to bring attention to this feature. It used to work and now it does not and have not for a very long time. I've tried several troubleshooting steps. I've tried most if not all troubleshooting steps Apple Tier Techs have provided me and none of them have worked. They've received me to send them logs from my iPhone, timestamps, etc. The problem is simple to recreate and it basically comes down to them going in and investigation the problem. If I recall correctly, when I had my Macbook Pro, I would receive notifications from it when someone accepted or rejected an event invitation, but not on my iPhone. I understand that iOS is making major changes and sometimes some features get phased out or mistakenly removed, but I hope that Apple is able to provide clarification on what happened to this feature specifically.