I think Signal was never able to run without a phone number because the security is bound to it.
Discussion
I have a phone number linked. That’s not the issue. They don’t let you register the device with qr anymore.
I’m stuck on a loop. After the count it goes back to the count. 
Okay, but that sounds more like a bug to me!
My iPad is also liked to my iPhone over qr and this works without problems 🤔