Nostalrius Begins - Quality wow vanilla realm (1.12)

Hi,GM. I wanna report a bug. We tried to put out the fire when we were doing Garr in MC, yesterday.And we successfully put it out(or dowsed the rune in the other words ). But after the killing of Garr, the fire reburned again and we cannot use the item on the rune any more,which means that we can not summon the 9th and the last boss. So, can we know how could we fix this or can you give us a hand?
the ID of the instance: 3810
We appreciate it if you can help us.
Thank you.

we used the item in a different position and it works now .
Thank you.