Hello, Shiro! Apologies that we have to meet under these circumstances. But it seems all parties are doing their best, and I am only here to help despite the murder assumptions.
You, unfortunately, will not be able to do it there. Untangling them in their tangled state and location is a logistical and existential impossibility. The longer you are sharing space between the two worlds the more entangled they will become. My best, and working, theory as I have discussed with Tiberius is that getting your group back to the other side, with an anchor should right itself. Your Outlanders are sharing one existence over two places. Breaking that bridge, or in this case closing the portal will sever that loop. Or should.
I have never done this before, only that I am a foremost researcher on the subject.