Heltec LoRaWAN test server based on TTS V3

Hi, I can’t connect to the Heltec LoRaWAN test server based on TTS V3 area.
The credentials are correct (user+password) and are the same ones I use to enter the area https://heltec.org/site/my-account/.
I always get the error:

{
“tails”: 3,
“message”: “error:pkg/account/session:no_user_id_password_match (incorrect password or user ID)”,
“details”: [
{
@type”: “type.googleapis.com/ttn.lorawan.v3.ErrorDetails”,
“namespace”: “pkg/account/session”,
“name”: “no_user_id_password_match”,
“message_format”: “incorrect password or user ID”,
“correlation_id”: “2e5416191c7c49a1abdee4b65a4dc6e4”,
“tails”: 3
}
]
}

Can anyone kindly help me?
Thank you very much
LL