i have the EXACTLY the same issue, PAP authentication failed error even I DID NOT change my password and my account is ACTIVE as what the TM NET customer service told me

later a long troubleshooting processs which they asked me to perform those stupid step like change DNS, refresh port and etc...end up they give up and they just reset my password, then now i can go in again, apparently something very wrong is in the TM NET exchange or server and they don't know what was going wrong and just trial and error to get the issue fixed ! WTF and lousy service !!!