Can't copy and save to flash drive

I've been backing up my computer so as to do a complete recovery. All of a sudden while sending pictures to a flash drive everything seemed to go OK. I can see the pictures transfer to the drive, close the drive and then go back in and everything is still there. If I properly eject the drive, remove it, then place it back in, all the files I transfered are now gone. There are other files on the drive that are still there but what I now add are totally gone. There's 27gb free out of a 32 gb flash drive. I also previously tried to copy to a 128gb flash drive and whatever I copied turned into weird characters from the bottom up while I watch it and I can't open the files nor delette them. I've rebooted and everything is still the same. Any ideas?

Your 32GB and 128 GB pen drives may be fake drives.

Try those on another PC and if the same things happen, no doubt about those being fake.

You may also tell us the model/make/ manufacturer of those pendrives, where you bought those and at what price?

Did you buy those because those came at a throw-away price?

Please copy whatever you have on those drives to another location and test those with H2testw.

Test for Fake USB Flash Drives ? H2testw | Portable USB Applications

I have the feeling that you're right. I bought the drives on ebay and now I'm sorry for it. I tried them in another computer and they fail there too. I'm now doing backup before doing the recovery onto an old 250 gb external drive. So far everything is going over nicely and verifying. Thanks for the hint. I had no idea that drives could be junk. The big one has no name and the 32 gig is supposed to be samsung. I doubt it.
Thanks again
Dave