I can't add a second gmail account in mail

I have been using two gmail accounts in mail. Recently one stopped working. I deleted it and now I can not add it back. No passwords have been changed. When I go through the procedure of adding a new account i get through googles 2-pass authentication. I then choose only mail as the app I want to link with. After pressing Done, nothing happens. When I look at the Activity screen it is blank. Connection Doctor only seems to recognize existing connections, not ones being created.

Yes, I did try adding a new account through System Preferences.

Any suggestions would be appreciated.

fyi. I am on a Late 2015 iMac, Retina 5K, 27", running High Sierra with 24Gb