I loaded an old save today to try out the 1.7 version and see for myself if that problem had gone away. Still there. But then i remembered to use the arrow keys to push my way through the portal and turns out it's just the mouse that doesn't work on it and i could finally use that passage.
Not a big issue, but could be worth including in a future patch, since most players (like me) don't even consider using the keyboard to move.
Anyway, problem solved, sorry to bother.
