I’m also pretty sure that this is not a certificate issue and we mixing up two things here.
The problem described by j-ed was indeed through the upgrade to catalina as Apple changed the allowed connections.
Now, I think we face a new issue. I have the same problem as Heziode.
The syncronization works well on iOS 14 (contacts, reminders and calender) and also on Mac OS Big Sur but only for calendar and contacts. As described, the reminders app shows the headline of the servername but doesn’t sync the reminders.
(The weird thing is: during the first setup all tasks were synced one time with Big Sur. But suddenly the syncing stopped and as I deleted and readded the CalDav-Account, reminders doesn’t show up at all)
So to be clear again. This is not an iOS issue and not the same certificate issue as it was during the upgrade to Mac OS Catalina. I’m using Let’s Ecnrypt certificates without any problems.
No ideas for now. I think the same issue is described in this post:
I have just called the telephone support, explained the problem to the assistant. After a while, it understand that this problem is beyond its competences, so it transmits to it’s “n+1”, re-explain the problem, and the “n+1” understand that the problem is probably a bug. So it create a ticket for there engineer team.
today I have a nearly 2h call with the Apple support. We figured out, that the sync work if I start my Mac in Secure Mode (start with pressed Shift key). The conclution was that some application block the connection.
After the call I tried a few things and found out that my issue was caused by Little Snitch (5.0.4). When I disable the Little Snitch network adapter in system preferences the sync work also in normal Mode. I wrote the Little Snitch support. I will report here when I got an answer…
After reading your post, I also tried starting up with Shift held, and sure enough, it works. However, I don’t have Little Snitch installed. I do have the Cisco AnyConnect VPN client installed though, and after removing that, it started working fine.
I wonder if there is still a bug at the OS level that causes it not to function when any network filter driver is installed.
Hi psychotic! I still have no feedback from the Little Snitch support. I will send them your info! Hopefully they have a better relationship with the Apple Devs/Support than I do. Don’t want to spent 2 more hours exlaining it some low level supporter…
Hi all! I got info from the Little Snitch support. They reported and/or follow other bugreports of the problem related to “Third-Party Network Extensions and Cloud Services” at Apple. Hope Apple take care of the problem soon…
I didn’t try the secure mode, but after the description of you two I could guess some network issue. As I’m not using any of your tools, I’m using TripMode (which blocks network traffic during mobile connections). The TripMode network adapter seems to be active all the time even if the program is not running.
After deactivating this adapter in the network seetings, the tasks are synchronising.
Since TripMode isn’t that important for me currently, I will leave it deactivated for now.
Thank you again for your contribution and your effort calling the apple support as this has a big influence on my daily workflow
Since disabling Little Snitch is not a real solution, I do not mark the subject solved for now.
I stay tuned for a working update of MacOS / Little Snitch that fix this issue.
For me, using MacOS Big Sur 11.2.1, the Reminders.app is still not showing any task from Nextcloud.
I started using the Mac just with BigSur a few days ago, never had a Mac before.
Same problem here! Has not worked since Big Sur was released… I use a Let’s Encrypt certificate, which apparently conforms to the cert requirements… But it doesn’t work. Tried various things suggested here, but does not work. Perhaps it will work again in Monterey?
I’ve got an interesting update to this topic regarding the iOS “Cannot Connect Using SSL” problem. When I proxy what the OS does using Charles, it makes the following requests:
So there are 405s. I wonder if these now need to be fixed with redirects? I tried adding the following to .htaccess: