Multiple Apple calendar email alerts

Apple calendar is sending multiple email alerts for a single event. I have 3 different apple devises but alerts are only set up on my macOS mojave calendar (and all previous OS versions).

It's always been a problem, but this past year or two it's worse as I've been receiving at least FOUR emails, multiple days at varying times, for the one same event — only one alert on one devise was ever set. The account goes through iCloud, of which I could find no setting to change there, and have checked the settings for the calendar app on my iphone 11 and my ipad mini but nothing that needed to be changed there either.

I know others have had the same problem and Apple specialists usually answer by trying to give the same lame instructions for how to use your settings, which was mastered long ago and isn't the issue. I believe it's an apple problem and the way iCloud behaves. Has anyone else had & been able to fix this annoying problem?

Thanks in advance.