Unreachable chest in the Dwarven Sauna, Thunderhead Peaks

As the title says, there is one unreachable chest in the Dwarven Sauna, the Blue Disk tomb, in Thunderhead Peaks. For some reason the special action skill area limit does not reach close enough to open this chest so I have missed this chest two days in a row now.

Video showing this: https://streamable.com/zpsq64

I have same kind of problem but within the dredge labyrinth where is those sonic guns. While hunting second chest in there,  Light of Deldrimor beam runs around one corner only like it would tell me to climb on top of the wall but no can do.