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 ?