Are there any known issues with the iOS app and Nextcloud 12?

Hi,

since the update from Nextcloud 11 (latest stable) to Nextcloud 12 I have connection issues with the iOS Nextcloud app as well as the Mac Nextcloud app. No connections are possible due to connection timeouts. Are there any known issues with those apps? Or if it’s a known issue, are there workarounds avaliable?
The web interface is working as expected only the clients are not able to connect.
Thank you in advance for any comments and answers!

OS: Debian Jessie
Nextcloud: 12.0.0

If there were, someone probably would have answered. I would check out if you see any entries in your server logfile (webserver/Nextcloud) when you try to reach your server. If there isn’t any entry, then check the network connection if there are problems (try via wifi/mobile network, try webinterface on mobile browser, check if you allow the client to use network connections on iOS).