Every time I add a new account it removes the defaults I’ve setup for the ones I currently have. For example - my personal account default reminder is set to 30 min. All other calendars are unchecked for “Show reminders”, “Show in Agenda”, and “Show in Calendar tasks”. After a new account is added my default reminder is set back to “No Reminder” and the other calendars re-check the other fields.
I don’t add accounts that often but when I do - I have to setup all the settings for each calendars again.