Can someone help with collision of unity 3d colliders

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Unity3D

So, I am trying to create a stealth game and to do that I created enemy and attached box with box collider component and IsTrigger is checked to the eyes of the enemy so that cube serves as vision and whenever a player enters that trigger, the enemy starts going after the player. The problem is as soon as a player enters the trigger, it glitches by
swiftly sitting and standing perhaps due to collisions of colliders of my player and enemy vision cube I don't know maybe it happens because of Unity itself and need to update the program or something like that

What I have tried:

Tried to use various colliders like sphere, capsule.