Yesterday I setup Manjaro Linux again. After this I'm not able to create the connections (new calendar, new addresbook) to my nexcloud-datas. The Error-Message says "HTTPS-Error (0)"
But I have access with my android App. This uses the same login-datas.

Operating System: Manjaro Linux
KDE Plasma Version: 5.16.3
KDE Frameworks Version: 5.60.0
Qt Version: 5.13.0
Kernel Version: 5.2.4-1-MANJARO
OS Type: 64-bit
Processors: 4 × Intel® Core™ i5-7200U CPU @ 2.50GHz
Memory: 15,4 GiB

Because i have access with Thunderbird Lightning and Cardbook the Problem might be a bug.
I will try to report it.