OnTriggerEnter on a fixed update?

Is OnTriggerEnter checked on a fixed update and not a frame to frame update? (no I’m not putting a function inside a function) I can’t seem to get ontriggerenter to work on every update, just occasionally.

Update() is for rendering frames, so it’s definitely not there. It’s FixedUpdate()

Yep, since these Events are triggered by the Physics Engine, they occur in it’s fixed update loop.
See here: Unity - Manual: Order of execution for event functions