I noticed in version 3.1 ‘Create or Connect with ORCiD’ button is missing on public profile page. However I found out there is already a fix for that thanks to @isgrim which is not merged to the master yet. Please see:
I will be good that gets merged. I have applied it to my installation and it worked.
Depending on when the review completes, we’re hoping to merge it soon for the next release of OJS. Meanwhile, if you’ve cherry-picked in some changes and they’re working for you, that sounds like a good resolution.
Public Knowledge Project Team