Evidence The NHI doesn't want to be noticed, they said so themselves
I think it's clear at this point that they are running some kind of experiment on earth and they don't want any contact.
1-1953, Albert K. Bender tried to hold a big event with 600 people to try to communicate with the UFOs using a precursor of CE5, before the event took place, he got the visit of three shadowy entities in his room who ordered him to stop his research and that they don't want to be disturbed in their work
https://www.youtube.com/watch?v=XtYl8DHDlmY
On a side note, a similar three entities took Bledsoe on a Bubble to the pyramids, he didn't see them directly as they were behind him https://www.youtube.com/watch?v=Em7P9g9zCYc&t=8648s
2-Kozyrev Mirror experiment was the Soviet equivalent to the CIA's Stargate program, but way bigger and involved thousands of people getting inside an aluminium spiral that somehow amplifies psychic power and out of body experience, other than the telepathic transmission of numbers and pictures to people in various locations, many saw UFOs and even the beings who told them that they come from a big star and they are watching humanity and that they should stop using the mirrors :
I saw a light on which I could manage to get to a flying craft it was a black hemisphere I saw a few doors I opened one door and found the beings with human shape but of smaller size, I asked them what they were doing and they answer they kept watching us, I asked them where they were from they said they came from a big star
My body got relaxed and light as soon as I closed my eyes I saw an object flying above then I was in a room I hadn't seen before a man was standing in the center of the room, his face wasn't seen, he began to speak slowly "your planet is in danger it is suffering, you have been in the mirrors too much, it's bad" then he said "there may be a disaster" I asked him when no answer came
Why Files : https://www.youtube.com/watch?v=a9hwXoCrEUs&t=1754s
All the details of the experiment can also be found in this russian documentary : https://www.youtube.com/watch?v=RrbIWesZ3QA
And in the book written by the two lead scientists : Cosmic Consciousness of Humanity - Problems of new Cosmogony.