> There seems to be a bug that when you interrupt a
> download (deliberately or by mistake) and then
> resume it, it will delete everything you saved so
> far. It is best not to touch anything (not even

If you cancel, everything not properly in the mirror at that point is deleted.
Just like obsolete files when a mirror completes properly.

If you cancel, there is NO resume. You can only continue or update.

Don't cancel.  Pause and resume if you must.