Well, first I think you shouldn't be using login with waitfor. You'll use print because waitfor captured the prompt and I don't think login will see it after that.

Second, you missed the whole point of using a regex there. If you read the Net::Telnet documentation on waitfor, you'll see that

my ($prematch, $match)= $obj->waitfor($matchop);
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gives you the string that matched in $match. So, if you use a regex like /(Password|Username)/ and a list assignment (again, I got this straight from the documentation for the module), then $match tells you whether you need to $obj->print a password or username string. Naturally if you print a username, you should then waitfor the password prompt and print the password. login attempts to simplify this stuff, but it's extremely picky about what it expects to see.

Your code needs to do the job of login, not try to work alongside it. A direct quote from the login section of Net::Telnet: "Consider using a combination of print() and waitfor() as an alternative to this method when it doesn't do what you want, e.g. the remote host doesn't prompt for a username."