Odd ASUSWRT handling of USB drives?

[Metazoan]

I've run into a very peculiar problem with a couple of Samsung flash drives that were formatted by, and used with an AX86U for file sharing. Both were formatted in FAT, via the Web GUI, by the stock firmware. Tried Merlin, but reverted back to stock, and then found one drive started to act like it is locked, and won't accept any writes or alterations via SMB connections. So then decided to reformat both and start over, but…

The issue now is that neither can be erased and reformatted, either on a Mac (by Disk Utility or Terminal), or a Windows machine (by File Explorer). ASUSWRT GUI fails as well, stalling during the formatting process.

The Mac Finder also struggles to dismount them, thinking that something is in use, and won't eject from either Finder or Terminal. Have to physically unplug them or the machine will sit stalled with a beach ball. (Despite that, the drives still mount, and don't act like they're corrupted and unreadable during subsequent attempts)

Does ASUSWRT do something to the drives, or use a non-standard way for formatting connected drives that causes them to act like they're locked, read-only volumes?

Last resort is to use the Windows Disk Management tool to clean and erase the partitions, but I don't hold high hopes that will work when I'm able to try it.

I can accept some sort of hardware failure as an explanation for one of the drives, but both would be a strange coincidence. An older generation of these Samsung drives served for eight years trouble free with my ASUS AC router, so I thought that experience would carry over to the new one. Silly me.

The whole file sharing function of this router has been a disappointment from the beginning, and this final straw makes me want to go grab a hammer from the garage and pound away on it.

 

[XIII]

The issue now is that neither can be erased and reformatted, either on a Mac (by Disk Utility or Terminal), or a Windows machine (by File Explorer). ASUSWRT GUI fails as well, stalling during the formatting process.

This usually means physical failure, but two at the same time?

 

[ColinTaylor]

I stopped using SanDisk flash drives when one failed immediately in this way, Amazon replaced it and that did the same thing. Been using Toshiba and Verbatim flash drives without problem.

 

[Tech9]

Some say many SanDisk, Kingston, Samsung branded drives sold on Amazon are fake. My experience is similar to Colin's - I killed two 32GB SanDisk Ultra Flair drives in days. Poor design, overheating and failing fast. Perhaps lower quality flash inside as well with fewer r/w cycles. One of them almost burned my fingers when I was removing it. There are pictures online of Ultra Fit model with melted plastic.

 

[bbunge]

I have several San Disk thumb drives that I have used for several years with no issues. USB2 and USB3. A couple are flashed as Windows or Linux install disks. Others are used just to store files to transfer between clients. I use Rufus to flash the ISO files to the thumb drives. I use SD Card Formater (WIndows utility) or GParted (Linux utility) to clean/format the thumb drives.
I have had every PNY thumb drive I ever bought fail.
I do not use the router to format a drive!

 

[Tech9]

Linux install disks

I killed one brand new SanDisk with Ubuntu Server installed on it. It was running burning hot >60C and died in 2 days. I just needed something to run the OS on for a short period of time for testing purposes. It cooked itself before I can finish.