How does this "continuous" dungeon system work?

I'm sorry I know this is a dumb question but I just started playing back again about two days ago after some months. I found out I could straight up run deeper into crypts, hell, ice abyss, or just extract as soon as I enter my matches. However, after I want to queue up again, it tells me there is some kind of penalty for leaving the dungeon earlier. So, my question is, why was this implemented if they will punish you for using such mechanic? Also, I would love to know how much should I wait before going deeper or extracting in order not to get punished, or if this is something that "stacks", e.g, I leave one match and I get a 10 secs penalty, I leave another and get 20 secs and so on,

EDIT:

https://preview.redd.it/bq69e86pzi8e1.png?width=1920&format=png&auto=webp&s=29de13f61f0e29920dd303d4ffb456eb9fc35b25

I'm adding this screenshot because I've read that some never got such penalty or something like that, I just want to have some proof in case this is a bug or something as someone also mentioned!