With my cloud space provider, I have observed that copying to a davfs2 mounted cloud space does only work if using tar, e.g.

tar -cf - sourcefile |tar -xf - -C clouddir

Doing the same (copying) with cp or mv results in the error messages:

cp: error writing ‘/home/kj/MyDrive/sourcefile’: Input/output error

cp: failed to extend ‘/home/kj/MyDrive/sourcefile’: Input/output error

I suppose cp and mv use a file creation method not appropriate for this kind of device. Either coreutils should detect the device and use a method better suited, or coreutils should restrain to be plain and simple and make use of a simple method working everywhere. (IMHO)