Help with CalDav sync on IOS 11+

ℹ️ Support
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1

Hi
I want use calendar app and synchronizing with iOS. I followed the user manual and used iphone with iOS 10.3.3，it can verify the account and sync successfully , but used iphone with iOS 11.* or 12.* can not verify the account (my server does not support SSL)
I have tried every conceivable setting and connection URL and have followed every guide I can find , but it still dosen’t work

I tried these methods:
1.use domain.name/remote.php/dav/ and domain.name/remote.php/dav/principals/users/USERNAME/ even only the domain name nothing else
2.change port to 80
3.service discovery is working , I tried change the connection URL to : domain.name/.well-known/caldav

do you have any idea what i could do ?
Thanks

2

The URL which is given in the user documentation worked well for me in the past.

4

thanks for your answer
the URL in user documentation worked well on IOS 10.3.3 for me， but can not verify the account on IOS 11.* / 12.*

5

I believe Apple has dropped support for synching CalDAV and CardDAV without SSL with iOS 12 or even with iOS 11.