Picked Devices for this enemy's powerset, but not Field Operative, yet it is stealthed.

[Shazbotacus]

It may be worth checking if other sets are granting unintended powers or power effects to minions when they are not selected for them.

[lemming]

I think you should post the build for the character and check the Stealth Radius in Combat Attributes.

 

Also, why would you not get Field Operative? It's provides Regen & Endurance recovery

[TheZag]

I think he means for an AE created enemy.