Optional Shibboleth Sign-In in Single-Journal Installation

Hi everyone,

I have an OJS installation (3.3.0-13) hosting only a single journal. When I enabled the “Optional Shibboleth Sign-In” neither the local nor the Shibboleth sign-in fields appeared. Instead I was sent directly to our institutional sign-in page when clicking on Login.
I was able to resolve this issue by creating an additional journal and then enabling the plugin from within the global Site Settings for all journals.
Did anyone have a similar issue or can confirm this?
I guess the problem is related to this post https://forum.pkp.sfu.ca/t/shibboleth-plugin-in-ojs-3/53442.

On another note: is it possible to configure the attributes that the plugin uses so that one could add the ORCID iD as an additional attribute for example?