Problem that seems to only affect Necromancers.
The source might be from the Thermal tubes and the stun-like effect it applies is considered a condition and is possible to transfer with Plague Signet (stuns the player) and “Necromantic Corruption” (stuns a minion) trait.
It’s easily to replicate, just have Necromancer near Thermal tubes while having Plague Signet and “Necromantic Corruption” with a single minion, resulting transfer of the said “stun” back and forth between the Necromancer and the minion.
I’m a casual PvE adventurer, I enjoy combat, adventure and helping, but not farming.
I rarely do PvP or Hard PvE, unless it’s organized.