Only did lich form, so don't know if this happened with others. Every change of instance, not just entry into quests but also in and out of random areas such as the Barn in Whallon explorers, turned it OFF, but the hotbar and buff display would still show it was on. (It was off bc aura would not tic until it was turned off and on again, for sp cost of course.)
Also, occassionally it did not go off at all when toggled. This happened repeatedly (4 times trying to turn it on one time, costing sp each time) and was with no mobs around or anything else that could break concentration, etc.