Sorry, you are absolutely right. I didn't mentioned that document, only a part of it (deactivate, etc.).
Now I did some deeper test, because I was not sure regrading the firewall. I activated the mac firewall, just to see if something was configured and still active in the background, but this wasn't the case. I checked my router (FritzBox 7270) but even here no firewall was active. I tried with iphone&hotspot to use antother connection. Same here.
I started PacketScope an could see that calendar and reminders are acive on port 443 and with this I also noticed that calendar is not syncing correctly (did not notice that before). I could also see that "notes" are active on port 993 which is working fine and also I can send and receive mails.
So, I took a look into the console log and found this:
22.11.12 14:48:45,161 CalendarAgent[156]: [com.apple.calendar.store.log.caldav.queue] [Account refresh failed with error: Error Domain=CoreDAVErrorDomain Code=3 "Der Vorgang konnte nicht abgeschlossen werden. (CoreDAVErrorDomain-Fehler 3.)" UserInfo=0x1234567890 {AccountName=iCloud, CalDAVErrFromRefresh=YES}] (I changed the user info for security reasons)
Some rows earlier I found this: 22.11.12 14:18:29,607 CalendarAgent[156]: [com.apple.calendar.store.log.caldav.queue] [Sync malfunction detected for calendar item with local UID: [354u345830580394582304582309548230495ß3].] (I changed the UID for security reasons)
This happens to me with my calendar but also with shared icloud calendars of my family members.
Does someone have an idea how to solve? Many Thanks ...
Jörg