Errors generated on SSD drives connected to R7000

Whenever I disconnect my hard drive (WD Elements 4TB or Seagate 1TB) from ny R7000 and check them with "chkdsk L: /f" on Windows 10, Windows finds errors and corrects them. Even if I plug them back in to the router and then test them again with chkdsk right away.
Is this expected? Is it a problem?