Stuck on "Enter the Twisted Domain" - Breach Questline

I've seen a couple of posts here and in other places about players getting stuck on the portal right after killing Xesht.

In my case, I could perfectly get out of there.

But what I'm struggling with, is finishing the followin step >!after meeting The Dreamer and entering the portal. !<

following
I'm even more sure that this is bugged, because on the second attempt to go in and move through the route, something (invisible) one-shotted me out of nowhere.

And here's where the path leads to.

Maybe there should be something in here?

How do I move the questline forward?

https://preview.redd.it/6ofvpsey7e5h1.png?width=1920&format=png&auto=webp&s=3eed2c77d3e2a40182b9d157bb96544710a784f2