flash drive errors

Tried many different ways to try and fix a 500 GB flash drive's errors, finally gave up as probably hardware fault. Details below.

Trying robocopy to copy large files, when a simple copy command fails - From

https://forum.rclone.org/t/using-rclone-from-local-to-local-file-not-cloud/11575

to

https://serverfault.com/questions/46655/how-do-you-limit-the-bandwidth-for-a-file-copy

to

https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/robocopy

Accidentally set this drive to offline in windows disk management - using the diskpart method did not work. The object is not found. No solutions for me from this link. Finally got it online again from the settings app, Right-click on the Start button and select Settings >

Navigate to System > Storage > Advanced storage settings > Disk & volumes >
 Properties button of a disk (except the system disk or Windows disk) > Status section >
Online/Offline button

- https://www.getusb.info/how-to-check-for-bad-sectors-on-usb-flash-drive/

chkdsk f: /f /r /x

Free space verification is complete.

 Phase duration (Free space recovery): 10.42 minutes.

An unspecified error occurred (6e74667363686b2e 164d).

 - https://superuser.com/questions/694422/what-is-the-fastest-way-to-mark-bad-sectors-without-data-recovery
Repartition Bad Drive (from Abstradrome),https://www.dposoft.net/rbd.html

Again, formatting fails.

badblocks (on Linux) - recommends using badblocks via e2fsck, but e2fsck does not support ntfs. (on rpi).

So, plan is to repartition into 5 100 GB partitions, and try format f: etc on Windows. Partitioned OK, but formatting the partitions fails. So, gave up as hardware fault.