Camera opens only with the rear function top down - how to fix?

If it’s OK for you, I would like to stick with English, maybe someone else can help us then.

I really don’t see the 5 digits you mentioned. Also: Do we speak about the rear or the front camera?

PS: This post suggests that you only need to restart your phone, if you see the green screen.
PPS: Have you tried with an alternative camera app like Open Camera?