I can’t find and access settings page for “Citation Style Language” plugin in upgraded OJS nstallation (from 2.4.7.1 to 3.1) . The “how to cite” section is also not visible on article page.
Marcin
OK. I’ve found where to find settings. They are available on particular journal website settings.
I’ve found another issue with the CSL Settings (OJS 3.1.0-1). When the user opens it (e.g. for the first time), all those settings actually get erased. I.e. all the options are unchecked. And the user may not realize that. Since he might only need to set the default style (at the top of the form), but he actually should also check all the styles he would like to appear. If he does not do it, he might be left with no styles in the ‘How to Cite’ block. Tagging @bozana
It works properly in my journal. Though I must have made some changes which I don’t recollect. I think I have just made my own custom vancouver styling.
Just to clarify, by the CSL Settings I mean those available through the back-end. Here is what I always see when opening the Settings:
(whatever I did before, all options are always unchecked)
It is marked always once i mark.
And when you close and then get back to those same Settings, are they still marked?
@Ph_We If you close and get back to the same settings, they are not marked anymore, but your settings are saved (check in the article view).
Yes, but when you get there for the first time, they are neither marked, nor saved. Actually the default settings get erased in this case.
When you get there again and mark some of them, they are saved, when you close it. When you open it again, they are still saved, but not marked 
I’ve opened the issue here: