I’ve got radicale running in a subdirectory (behind nginx), seems to work from a web page with e.g. https://example.com/webdav/user/contacts.vcf/ and https://example.com/webdav/user/calendar.ics/ and the .well-known seems to redirect correctly when I try e.g. https://email@example.com/.well-known/carddav
But when I enter https://example.com/webdav/user and username/password into davidroid, my server logs (nginx access/error, and radicale log) don’t show any response, and davidroid says it failed to configure.
Debug logs of davidroid look like http://sprunge.us/LHbf
I did have owncloud+apache before on that hostname, with a different ssl cert, which worked fine. I tried the Settings option to purge remembered ssl certs, but that didn’t help. Turning off system CA had no effect either.