I really hate this mechanic

After you die when you encounter boss all of content are gone.
I try to clear everything first but for Mire map when I go to boss checkpoint after that I try to clear map but I die and then all of content are gone.
Is this bug or feature ? I really Hate this

Didn't they fix this in some patch? I think I read about it in the patch notes... I dropped this league in the first week and I don't know how things are now... But this mechanic looks just RIDICULOUS!