I was also having trouble with phasing at the bottom southern beacon and leaving BRH and coming back didn't solve it. I had another quest in the same area called "Restoration: The Bradensbrook Investigation" and after completing it, the area stopped phasing and I was able to place the last beacon.
Honestly, all the complaints on this and this is not a bug and is a result of the area becoming phased for the purpose of a cosmetic artifact appearance that if you don't get it before the release of Battle for Azeroth becomes unobtainable. Instanced and phased areas appear all the time throughout the game that do similar things. Even the questline in Snowblind Mesa leading up to the entrance of Neltharion's lair does the same thing in some cases. There are similar issues that are part of classic content such as the area in Redridge Mountains called Render's Valley that becomes Render's Crater upon blowing up the Blackrock Encampent in the area with Seaforium Charges. This is just part of the game and again is not a bug and to be honest not a big deal complete the questline and move on with it and don't complain. Its not as big of a deal as many players have made it on this post. If you are trying to unlock the Challenge Artifact Appearances before August 13/14 then this has to be done anyway. It takes like 5 extra minutes to finish the quest chain and then you can get your beacon.
Honestly, all the complaints on this and this is not a bug and is a result of the area becoming phased for the purpose of a cosmetic artifact appearance that if you don't get it before the release of Battle for Azeroth becomes unobtainable. Instanced and phased areas appear all the time throughout the game that do similar things. Even the questline in Snowblind Mesa leading up to the entrance of Neltharion's lair does the same thing in some cases. There are similar issues that are part of classic content such as the area in Redridge Mountains called Render's Valley that becomes Render's Crater upon blowing up the Blackrock Encampent in the area with Seaforium Charges. This is just part of the game and again is not a bug and to be honest not a big deal complete the questline and move on with it and don't complain. Its not as big of a deal as many players have made it on this post. If you are trying to unlock the Challenge Artifact Appearances before August 13/14 then this has to be done anyway. It takes like 5 extra minutes to finish the quest chain and then you can get your beacon.
Some people have posted that they completed it and still didn't get it to work. Way to spend all the time typing that just to come off like a complete douche bag. If you're not going to say something helpful, stay off the forum where people are looking for HELP.
I had this same issue, i tried to abandon everything in my quest log and it did not fix it. So after reading on some other forums i found that i had an artifact quest that i had not finished yet just south of where the beacon needs to be placed. After i completed the artifact quest i was able to set the beacon no problem :)
Had this same issue. Did the legendary quest you get in Dalaran from the Six mages, for Resto spec on my druid and after receiving the gift for the artifact weapon from them, came back to the zone and tried again. Worked.
Trouble is, NOW as of today as 50 I am trying to do that artifact quest in Bradensbrook, but surrounded by lvl 60 that tromp you.
So that may have worked before, it is not viable that way nowâŠ
Yours is a different bug than the original one this thread is about. You need to start an all new thread rather than necroing one that died 2 years prior, before the current expansion was even released. That way, the QA team can see the new issue rather than seeing an old thread resurrected from the dead.