Ai sight perception doesn't detect the character in closer range

Hi everyone,

I’ve been playing around with the ai perception component sight for my new stealth game and I figured out that as much as u narrow the peripheralVisionHalfangleDegree,the ai perception doesnt spot you if u are too close too it.
Any idea why is this happening??is this a limitation in the ai perception component??
I attached a photo describing more the probleme,the peripheralVisionHalfangleDegree angle is at 30 degree