Unable to delete old Apple ID alias email addresses from iCloud Calendar Send & Receive on iOS/iPadOS.

I can't delete old Apple ID "@me/mac/icloud" alias email addresses from iCloud+ > iCloud Calendar > Account Settings > Send & Receive > Sending/Receiving on iOS/iPadOS.

There are a total of 12 email addresses in the drop down menus; (3) of them are original (15+ yrs) Apple ID "@me/mac/icloud", (8) of them are (2) different old/deleted "@me/mac" alias', (1) unknown "@me/icloud", (2) "@me/ilcoud" still using, and (1) recent new "@icloud" I created for work after deleting one of the original Apple ID alias', which appears/disappears and changes in various app default email settings (Mail,..).

It's been frustrating to say the least. Same w/ what email Calendar uses to reply for invites (was using Apple ID email).