Calendar Reminder Pop-up can't be disabled

eM Client on MacOS here. Version 10.4.4867. Concerns Exchange accounts

I want to totally disable the calendar reminders pop-up. I manage a large team and I get pop-up’s for all their calendar events. I know how to disable that in the account properties, but every time I reopen someone calendar (I don’t have them all enabled by default), the “show reminders” in properties is enabled automatically. I keep turning this off but it is bore.

Disabling the pop-up in eM Client settings under Notifications is not possible “Sorry, but this option is not available for this item”.

How do I get rid of these pop-ups once and for all?