Robot arm disappear randomly

i recently added a robot arm to my avatar and it randomly disappears in game i know its not world cause i can see my other arm and limbs just not the robot arm

The only time I’ve randomly seen limbs disappearing is when it’s a separate mesh with a bounding box that’s too small.

But I think it’s highly unlikely that this is the case for you, so you might need to provide a few more details. Otherwise it will be difficult for someone to help you out!

i removed a robot arm off a model in blender and decided to move it to my avatar when i attached it. it was perfect but when i go in vrchat and look in random locations it would randomly disappear i know it happens to multiple avatars when i add clothing or objects to a model but i dont know the cause.

i fixed it by clicking update off screen on