DOIs not assigned when publishing an issue

Hi @bozana, I’m asking to you because of this post you wrote in the old thread cited by @sourcedump opening this one.
In OJS 3.1 we had the automatic creation of DOIs, from 3.2 we have to assign them manually… why?
DOI Plugin still have settings for automatical assignement, but in our OJS 3.2 it doesn’t work anymore, as you can read here.
Can you help?
Best regards
Stefano