Why Authorization screen ask 2 times instead one ?

What's happening?

Why Authorization screen ask 2 times instead one ? What technical reasons do that ?

I tried to reproduce on my side I have been asked 2 times to authorize. I would say that it is one time too much. Especially cause we struggle with the fact it is frightening (applications/hubl#864)

If users have to manage it several times it's painful.

(To be confirmed but I've heard users had to do so till 4 times)

Old accounting Protocol