Merc with HH----Trickster rare monster breaks merc AI forever

Mercenery killing with Headhunter steals rare monsters abilities. One of these abilities is the Trickster, the monster that creates a frost wall and runs out.
This is what the merc does but forever after it steals the mod it runs away forever even after 1 minute passes and the mod worns off. You must leave the map to reset Merc AI or it's stuck in that Stupid mod forever.

If a player steals trickster mod it doesnt make them ghosted and unable to attack so why does the merc have it, it basicly disables carry Mercs.