FTP password length

[liquorvicar]

A user has been complaining the, when resetting a domain's FTP password, long passwords don't work. I tried it out and he's right. I reset an FTP password to a new 16-digit password and I then couldn't log in via FTP or sFTP. Is this a limitation of the OS, FTP/sFTP, Plesk? What is the limit and shouldn't the Plesk GUI be aware of this and not let you add a long password?
Ta

 

[f6n5i4qweuf]

Ten years and still not fixed...
What is the reason for this limit? When storing passwords in hashed form instead of plain, the length should not be a problem.