Is OAuth broken?

It does seem like something weird is still going on. I saw something similar happening a few days ago. After hitting the login screen, then logging in, I would be redirected to the developer dashboard. From there I had to close the login, then when I would retry the request it seems it would cache my credentials and properly direct me to the authorization screen to select devices. The authorization seems to work as expected from there for me (via Postman and SharpTools) so I can’t reproduce the error message you are seeing.

I put together a quick video showing this in Postman: (I would recommend viewing fullscreen and in full resolution)

It seems the loading of the devices in the authorization window is a bit slower than normal as well. It’s not considerable from a solid connection (eg. desktop), but it’s pretty noticeable on a slower/more latency burdened connection (eg. mobile).