In Season 5 Episode 19 : Option Two, the Remoraths are introduced. According to Deke,
Deke: The Remoraths are marauders. They're intergalactic scavengers with no planet of their own, so they just take from others, and and wherever they go, darkness follows.
Fitz: Darkness? That's a little vague.
Deke: Well, it's not the concept of darkness, it's literal darkness.
Later, in the episode, Fitz claims that the Remoraths possess some sort of EMP that render all electronic devices (such as icers, walkies etc.) useless. And it is shown across Episode 19 through 22 how Remorath's presence affects electronics.
However in Episode 21: The Force of Gravity, in at least two instances, (listed below) Coulson's prosthetic electronic arm seems to work just fine around the Remorath warriors.
- When Coulson uses his prosthetic arm's scanner to find a weakness in the cell walls and,
- When he creates a shield to protect himself and May from the shooting Remorath
How was Coulson's arm able to function normally around the electronics-blocking Remoraths?