I am pretty sure the mark is still there. Because when Ivan was sick, he didnt want Hyun to come. And that would be because his pheromones are bad for a marked person.
But it is weird that they havent talked about it or shown it since then so i am not sure if its still there or not.
I mean no harm but the storytelling do skips important details and some parts are confusingly vague if not literally contradictary.
My guess is that they will soon talk about the mark and have the meetings with the doctor to take it off
OR at one point the mark will have suddenly disappeared and we will have to guess when it happened by ourselves. Because thats the kind of storytelling we have in this story.
Also im pretty sure Hyun and Alek will lose their emotional link when the mark is gone. So I strongly believe that the mark is still there for now.

For those confused about Alek feelings Hyun's emotion (dont read if you arent up to date)
Remember when Alek raped drunk Hyun at the begining of the story? Well he got lost in the pheromones and ended up marking Hyun.
But he decided to not say it because its only a dangerous mark that ties down Hyun to Alek so no need Hyun to be aware of it.
Therefore Hyun was unable to take off the mark because in the hospital meetings they had Ivan instead of Alek
Eventually, Hyun was about to die due to the mark
Alek knew everything about the marks, the side effects and how to treat it. Guess what? the only option was to fuck Hyun and create a mental connection between. A connection so strong that Alek could have controlled Hyun to "steal" him from Ivan. But he decided not to because he decided its time to become a decent human being after all the crap he did. So now they are mentally connected.
So this is why Alek can feel Hyun's emotion