Files disappeared when I presumably hit undo while transferring files from Android

[sonic robin]

Just a recommendation in general: Just copy your files first, and delete the source afterwards
That way, if something goes wrong, you still have the original.

Why a Recuva deep scan doesn't work is probably because you're using an SSD(?). On HDDs there is a much higher chance you'll be able to get deleted files back. On SSDs you can pretty much say once it is gone, it is gone.

[sonic robin]

Ah..
But did you try to scan the source (Android) with Recuva? Because that probably won't work at all due to MTP
If you tried scanning the HDD then you should get some results at least...