I discovered a part of the problem. On my main when i try to do the weekly legend, the root one is not available to me yet. The problem is that for that one at least you need to do “The Empty Cradle” cradle story line that starts with the quest The Listener
After that you suppose to do In the Name of the Goddess but this one never started for me. To open the weekly Root of the World you suppose to follow that chain all the way up to The Empty Cradle but since the chain is broken (idk why still is to this day) you cant progress towards Chronicler of the Haranir
I have tried everything i could think of, even going with a fresh lvl 80 throw the Harandar main campaign and still nothing. What a waste of time.
Edit: By chance i found out what character's of mine started this chain. That week i had to repeat one of the quests, then the following week a new repeat but the next week after that i got the blue "!" for the weekly plus a yellow "!" quest for the next part that was unlocked for me. So i continued week after week on the same character until i got the achievement.
Seems that the developer of this quest chain only thought of it from the POV of one character or more likely they messed it up locking it for alts so you cant exploit it and finish all in one week.
GL everyone, i hope this helps you avoid all the research that i did!