I just upgraded my forums to IPS4. The archive feature was turned on and it archived a good 75% of my community. I am unable to manually unarchive the topics or if I turn off the archive feature, It doesn't unarchive the posts when it said it would. Has anyone run into this before? Can this be fixed? Should I create a ticket?

Can this be fixed? Should I create a ticket?

Yes, it can. Yes, you should, they are the only ones who can fix it.