Files (Gnome) - Transfer failed - created 0kb files, how to replace?

Hi folk.

Problem 1:
I want to transfer my HDD #1 to another external USB HDD #2, so I copied it with the default file explorer from Manjaro, Gnome (I think it’s Nautilus). But after I double-checked it, I saw several 0kb files, so it’s missing over 700gb of files. Both HDDs are fairly unused.

Problem 2:
I can’t replace only smaller files with ‘Files’. What application can I use instead or is there some other way? Thanks.