if the same thing is happening on multiple computers the drive is likely dead. contact the place of purchase for a return since you are withing 30 days of purchase or contact sandisk support and submit a warranty claim.
My 128gb ultra fit has also died. It got very hot when plugged into a usb 3.0 slot, but ok in usb 2.0., but why use a slower port for a faster drive?
It reported errors while checking witn h2testw too, around 1mb per 1gb checked, so I decided to reformat it to fat32 and re-check it. It died while checking!
I don’t understand why Sandisk continue to sell these, as I have read many, many posts from others with similar problems.
This one is going back for sure.
It’s a pity, as I don’t have a drive big enough to hold my, very large collection of CDs to play in the car.
FAT32 doesn’t support drives that large. If it worked you would only get access to about 1/3 the drive.
It appears that these drives hold a lot, work great for being read but die when people try to fill them initially rather than over time. If you load all your CDs to it in a USB 2 port it should work in your car ok. It will just take longer loading it initially. Then replacing CDs on it periodically should be ok in a USB 3 port.