I replied to someone else, but perhaps I need my own topic. Students were able to log on two days ago but cannot get through the Sign On With Google process without it being kicked back to the same window. Two students had their tabs open still and continued to be able to work, and the same happened with mine which was not closed.
Sounds from here like a whitelist from you will be needed.
Thanks for your help!
Mill Valley School District
Mill Valley, CA