multisite with same setting, error while processing the authentication request

While we installed this test site for different plugin, found 401 error sending test mail, and got “error while processing the authentication request”. after click “Allow plugin to send emails using your Google account.”

But both https://lt.johocen.com and https://lt2.johocen.com set up the same Client ID and Client secret, also same Authorized JavaScript origins and Authorized redirect URI.

Appreciate any help to guide us where we should look into…

Versions:
WordPress: 4.9.5
WordPress MS: Yes
PHP: 7.0.27
WP Mail SMTP: 1.2.5

Params:
Mailer: gmail
Constants: No
Client ID/Secret: Yes
Auth Code: No
Access Token: No

Server:
OpenSSL: Yes
PHP.allow_url_fopen: Yes
PHP.stream_socket_client(): Yes
PHP.fsockopen(): Yes
PHP.curl_version(): Yes

Debug:
Error while sending via Gmail mailer: {
“error”: {
“errors”: [
{
“domain”: “global”,
“reason”: “required”,
“message”: “Login Required”,
“locationType”: “header”,
“location”: “Authorization”
}
],
“code”: 401,
“message”: “Login Required”
}
}

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