Hello,
I've been using Jira recently and I came across a problem that I don't know how to fix it.
I have to Jira instances. when I try to link an issue to one on the other instance. it works for all issues except issues from a specific project. It used to work but now it won't.
every time I try to link it I will get this even though for other projects it wasn't needed :

and when press authenticate I get this page:

afterward, when I press the link nothing changes.
and it only happens for specific project issues.
Update* Now it won't work for all projects.
Please if you are familiar with this problem help me.