Google OAuth Issues

Hello, I’ve been trying to configure a few of the google integrations, and the OAuth isn’t working for me. I’ve followed the steps to the letter, and even started over and tried different tutorials a few times, still at a loss. For the GMail and Youtube integrations, I get as far as entering my clientID/secret, selecting my google account… and then this page, from which I cannot progress:

I found an old topic from a user with the same issue, but nothing in there helped.

Oddly, I was able to set up the Google Assistant and Google Assistant SDK integrations earlier, and the Google Calendar one today (with some messing about, it also got stuck on that screen initially).
Any ideas?