@baris Yes. I see also that there is a problem for some other pages like /search ... I will see if I can get it work for all (I thought there were just one place/hook to parse title for all uses but it's not the case).
A few weeks ago we weren't checking the slug for correctness. So https://community.nodebb.org/topic/2647/anythinghere was working. But if you had images in the topic in the form of  this was causing an api call to the topic and loading the entire topic to solve that we started checking the slug.
If we can find a solution to that image problem we can go back to ignoring the slug.