error multisite with gmail OAuth

Replies: 0

Hi, plugin works very fine in the main site http://www.mydomain.
I set up the wp-config lines and the admin part is deactivated.
in the other subdomains I have error :

ERROR IN DELIVERY OF THE EMAIL: The WP Mail SMTP v1.8.1 plugin detected this error the last time you tried to send an email:

Mailer: Gmail
{
 "error": {
  "errors": [
   {
    "domain": "global",
    "reason": "required",
    "message": "Login Required",
    "locationType": "header",
    "location": "Authorization"
   }
  ],
  "code": 401,
  "message": "Login Required"
 }
}

Any Idea how to debug that ?
thank you
best