The problem comes from Deck. Please follow up here: https://forums.bitfire.at/topic/2427/404-when-uploading-a-locally-modified-resource
When scanning for calendars, my DAVDroid 0.8 from F-Droid does not show group calendars. The server uses Baïkal, although with a custom frontend for creating calendars and such, and because I don’t administrate it, I don’t know the version (maybe it is visible from the logs?)
I had a look at #345, but well-known path detection is not supported by the server.
I suppose this is the same as #528 but AFAIK Baikal doesn’t even have group calendars. Or are we talking about Baikal 2?
Please follow up in #439.