Reinstalling rear wheel (Nexus 7 + Inter-M roller brake) but wheel won’t slide into dropouts

I am trying to reinstall my Nexus 7 rear wheel but I am stuck. When I put the chain on the sprocket, the wheel won’t slide fully into the dropouts. I think the chain doesn't let it move. Without the chain, the axle goes in fine.

Also, the cassette joint and the reaction arm look misaligned. They point in opposite directions, and moving one seems to move the other. Is that normal, or did I mess something up? I am freaking out a bit, what should I try?

Note: bike is upside down in the photos, and I removed the chain tensioners . The wheel also won’t slide in with the chain with them on.