some minions still fall through the floor

so i must admid i havent seen this to often but it still happens on skirmishes and scenario's
some of my minions hust flatout fall through the floor of my dungeon being unable to interact with anything.. just yesterday i was playing a map from workshop and i had 4 juggernaughts slumming it in my basement, now ive tried using recal in their unit portrays and in the past this sometimes help.. but in this case it didnt.. i see this happen in my own dungeon.. but sometimes as well when killing a dungeon core, minions being stuck in it even after its destroyed