Thank you for the update. I will try with the ::cisco too.
However, in the meantime I was able to get it to work-

  $telnet->waitfor('/Username: $/i');
  $telnet->print($username);
  $telnet->waitfor('/Password: $/i');
  $telnet->print($password);
  
  $telnet->waitfor('/>/');
  $telnet->errmode("return");
  $telnet->print('enable');
  $telnet->errmode("return");
  $telnet->waitfor('/Password: $/i');
  $telnet->errmode("return");
  $telnet->print($enpwd);
  $telnet->errmode("return");
[download]

Key here is the errmode = return.
It works for all the scenarios below for Tacacs, console etc-
1) username, password, enable password
2) username, password
3) enable passowrd etc.