I was using roundsync as a WebDAV server and using rclone from my laptop. I didn't find another WebDAV server that would be better. I tried syncing with my phone as an FTP server, but I ran into an error similar to this, which is strange, since that issue is from 2019. Maybe I got the error before I upgraded rclone on my laptop. Ftp: empty directory yields "directory not found" error
Thank you. I might set up rclone on Android or focus on one single file.