I too lost the buff because I flew just outside the area from a ham-handed keyboard error. I tried regaining the buff, but nope.
I was able to complete “The Race” after losing the buff. Let me stress, although it was doable, it was very much the opposite of fun. It took about 20 or so minutes of pure murder-hobo, two deaths, and much cursing at the monitor.
I can’t light one of the orbs to get the buff at all. Deleted cache and wtf folder, went back and now no orbs will light at all.
I was working on it and the buff just suddenly went away and i had 50 minutes left on it. I have no idea why. My sis and i were getting pieces.
You don’t need the buff to get the pieces.
No but trying to clear out Elite mobs at level 69 is definitely a challenge lol
Same issue. My wife cannot get it either.
Same here, so disappointing. I actually missed a couple of objects and decided to find them myself rather than get help/cheat 
Of coure had to pick a few fights and one with a rare which took forever. Ran out of time , fail!!! Should have been warned that this last day was about clock watching rather than careful methodic searching even though it did demand careful attention. Marple/Perot would be disappointed too. So I can do it again on another toon but racing the clock puts a whole new complection on the task.
Well, this afternoon I recieved responce from blizzard on this issue. Their response was as follow:
Warm Greetings, Nitknight!
Thank you for contacting Blizzard Entertainment’s support team.
This is Game Master Nyrilmos, :3 Here to assist you with your gaming woes today. ʕ•͡ᴥ•ʔ♥ฅʕ˘ᴥ˘ʔ
I can see that you’re stuck on Secrets of Azeroth as the Faith of Tyrhold buff was removed.
I will be more than happy to take care of this matter for you right away. (ง︡’-'︠)ง
As a fellow player just like you, I understand how much your in-game characters mean to you and how they can hold emotional value beyond their in-game utility, thus, I absolutely comprehend your standpoint.
I have investigated the matter thoroughly, and I will share my findings in detail right now. In fact, I had the same issue myself earlier, I got confused after losing the buff, I Could not regain the buff but finally used brute force and killed each room, put the idol on, and retrieved the items to combine and went through the rest of the quest line to get the achievement and mount.
Also, a player stated on wowhead that they obtain the buff by walking up to the giant face near the center and using the torch. they did not have to fly by each orb. Just went by the face, lit their torch and they got the buff.
Moreover, at Blizzard, we believe that our players are our family, and we are always striving to ensure that you feel supported and valued. We recognize the time and effort you have invested in our games, and we are grateful for the trust and loyalty you have shown us, and for the time you took to reach out to us regarding your quest, and we strive to maintain our position of being at the top of your expectations, and we will always keep working hard to exceed them too.
If there’s anything else we can do to assist you, or, even if you would like to share your adventures or talk about your favorite games and events, please don’t hesitate to reach out to us via a new ticket. We are always here to listen and provide the best possible support to our players.
Farewell, Nitknight! May your adventures in Azeroth be full of epic loot, unforgettable experiences, filled with happy surprises along the way! (｡•̀ᴗ-)
Now, I was personally able to complete the achievement, but I had to hit level 70, and get better gear to be able to fight the enemies in the way of the items to be attained. Hopefully, Blizzard can address this sooner than later so the rest of you may be able to finish it before the opportunity is removed.
Best of luck all!
The issue turned out to be more complicated in the end and a Dev kindly waded in and fixed things, did the last run entirely on an alt and finished it. Thank you Devs
My problem is that it’s the dragon guys turn to have something for me but the blue question mark won’t appear about his head. Im going to try and do rhis on my priest instead and see if it works