I am having some trouble with a Nextcloud server. I set up a digitalocean droplet to test contact syncing for work. I went with the setup that I use at home, which is Yunohost and Nextcloud. This was/is working fine to sync contacts with iOS using the built-in support for CardDav accounts in iOS.
I made a snapshot of the server and rebuilt it on a work account (also Digital ocean). I reconfigured it for a new domain name, and got a letsencrypt cert. I can login and manage the admin and user accounts.
I set up an iPad to use the new server, and it seemed to work fine. However, I subsequently tried a couple other iPhones, and it won't connect to the account.
It isn't a fail2ban thing, because on the same apple devices that I can't connect to the accounts on, I can go login to Nextcloud in their browser.
What is happening?
Edit: I seem to have fixed it by reinstalling the server from scratch. I wanted to eliminate any problems that may have been caused by restoring from a snapshot previously linked to another domain. Everything is working at least for now.
I am not seeing anything (relevant) in the Nextcloud logs (as viewed from the web app). In iOS I get a message about SSL verification failed, and do I want to try connecting without it. Either way it cannot validate credentials. I know the username and password are correct (tested multiple times/work to login in the browser), and the SSL cert is valid.
Also /var/log/Nextcloud/ is empty. Where else should I look for logs?
The issue could still be a fail-to-band issue if fail-to-band is looking at the user agent string (I'm not sure fail to ban looks at the user agent string, but it might be worth checking out.). The user agent string would likely be different on a mobile app versus a browser login.