Actually, I'm going to say the two demons are not affected by the cloaks because they both have Truesight.
Cloak:
QuoteWhile you wear this cloak, it projects an illusion that makes you appear to be standing in a place near your actual location
Truesight:
QuoteA monster with truesight can, out to a specific range, see in normal and magical darkness, see invisible creatures and objects, automatically detect visual illusions and succeed on saving throws against them, and perceive the original form of a shapechanger or a creature that is transformed by magic. Furthermore, the monster can see into the Ethereal Plane within the same range.