After "copy" "paste" the hardrive does not working anymore

"I know this is not an immediate solution but for future choices.

These name branded external drives are the worst possible choice. Always, always purchase a SEPERATE case/controller and hard drive. Again, why? Often the branded ones have the drive’s circuit board and the USB port imbedded in the same circuit board. If that circuit screws up you are often lost. The component solution (like a good hi-fi sound systems) allows you to easily take the drive out, if the USB part goes bad, and recover your software in another system or case.  If the drive dies replace it or upgrade to SSD or larger capacity. A no brainer!"

A “block error" means the hard drive is dying.

"I had the same issue with a brand new 2T external hard drive, in my case the drive would systematically stop working when it reached around 750Gb data storage. I could still format it with gparted and it would be usable again but the problem is still there and I haven't found a fix to this fault yet, so I'm left with less than half storage capability. That said, worst case scenario you can't get a refund/replacement, you could try doing some tests with utilities like smartmontools(cross-platform) and badblocks(GNU/Linux) and hopefully solve it

Update (01/12/2021)

UPDATE: After disassembing, connecting the disk to the pc through SATA and wiping it (zero-fill,1 pass) the problem was gone, all disk space usable, no more r/w errors - along with the terrific slowdowns and frequent hangs - occurred during file transfer. So I put the drive back in its USB enclosure, formatted it and tested again, still works fine, so I suppose one can replicate this without taking the disk apart. From what I understand, reinitializing the hard drive allows the identification and correction of damaged sectors; sure it takes a while, but mkfs utility did the trick for me. On Windows there's a variety of free tools (most of them included in hirencd) to diagnose/fix hard drives presenting software-corruption symptoms"