good question indeed! do you have any other plugin installed that modifies the login behavior in any way?
Oauth2 consent when signup/login with Gmail – Google API via the Ultimate Member Social Login Plugin.
It recognizes user and prints name/login when:
logger Plugin_UltimateMembers_Logger
_server_http_referer https://accounts.google.com/o/oauth2/auth?response_type=code&redirect_uri=https%3A%2F%2Fmydomain.com%2Fregister%2F%3Fprovider%3Dgoogle&client_id=111xxx999-randomstring.apps.googleusercontent.com&scope=https%3A%2F%2Fwww.googleapis.com%2Fauth%2Fuserinfo.profile+https%3A%2F%2Fwww.googleapis.com%2Fauth%2Fuserinfo.email&access_type=offline&approval_prompt=auto
Ultimate Member may change some usermeta or other important value. Looking at the logs it appears when a user signs up without Oauth they are the ones not recognized.
I will ask them about the possibility to investigate.
thanks
stu
