Huh. Why is Android displaying a sync error then? That is outright weird.
I guess I can help with beta testing a little, yeah, but don’t have much free time. But I know how to write bug reports. 😜
I get “E/A-Fehler: No peer certificate” even when selecting “http” (not “https”) for my server (ask me for an url).
It has a self-signed certificate, but should work with http.
Can you please send the URL to play@bitfire.at? I have use http:// to test with HTTP only servers and I didn’t experience this problem.
You have a mail.
OwnCloud seems to redirect to https:// by default (or at least in your installation). So I will close this issue as a duplicate of issue #3.