Is there by any change your site configured to use different password encyption than your server? Do you store your password as sha1/ms5 hashes or plain text? Make sure both server and www are setup to treat password same way.
I kind of don’t get what you mean with “sample”. Do you mean Characters used as sample by AAC or you used it in terms of “example”. Does it happen for all accounts in your server? Maybe some of th have different passType, some has hash and some plain text password.
For most servers it’s in config.lua
But some distros use base32 encrypted passwords