When you use two STC ports do PPPOE testing, one port is PPPOE Server and another port is PPPOE Client.
When PPPOE client setting the username/password different with PPPOE server, the authentication is also successfully.
The PPPoE server will always succeed authentication regardless of what its set at and what the client sends it.
The only time authentication will fail is if there’s a mismatch PAP or CHAP in authentication protocols between the client and server.