Ok I've got it. In my case, I was using a two-step auth account.
The password configured in empathy was an application-specific password, which method seems not supported with OAUTH2.
After removing the empathy account and recreating it, I've got the login/password that clearly specify to not enter the application-specific password but the account password, then the 2nd step password.
Then it worked.
Ok I've got it. In my case, I was using a two-step auth account. specific password, which method seems not supported with OAUTH2. specific password but the account password, then the 2nd step password.
The password configured in empathy was an application-
After removing the empathy account and recreating it, I've got the login/password that clearly specify to not enter the application-
Then it worked.