HTTP 404 error with DAVx under Android

Note: A few very similar questions emerge in the search, but I believe the actual issues they address are different from the current one.

I have attempted configuration of DAV calendar and contacts synchronization through a new Android installation running the Nextcloud app and DAVx5. However, configuring a connection to the server account on the device fails. The application creates debug information that is quite detailed, but I believe the section describing the HTTP exchange illustrates the cause of the problem.

Request{method=POST, url=, headers=[User-Agent:DAVx5/4.2.4-ose (2022/10/26; dav4jvm; okhttp/4.10.0) Android/12, Accept-Language:en-US, en;q=0.7, *;q=0.5]}

Response{protocol=h2, code=404, message=, url=}

Why would the address used to attempt login be reported as a missing resource by the server?

The server is Nextcloud 25.0.1. The client is Nextcloud for Android 3.22.3 and DAVx5 4.2.4-ose running on Andriod 12 as LineageOS for microG.

I’m having a similar problem. I’ve been using DAVx5 to sync with Nextcloud for a few months without problems. About a month ago, I just started getting these random 404 errors for two of my three calendars. I have no idea why. I didn’t change anything in my NC setup.

Nginx shows that it’s sending a 404 response to REPORT requests for those two calendars but not for PROPFIND requests. Strangely, a REPORT request is never sent for the third calendar which isn’t having any issues. Syncing on all calendars seems to be working though.

For me, it started to work after I simply waited a few days. I think the reason was expiration of certain cached credentials.