I'm not sure how it would do a file system check before decrypting. I would expect the file system data structures to be encrypted. So I'm still confused. I would expect MacOS to display the password prompt almost instantaneously, since, what else can it do with an encrypted drive?... I suspect that the delay in showing the password prompt is due to doing a file system check prior to decrypting, and the delay after is from doing another file system check on the decrypted file system after decrypting. ...