If you have an object with an UdonBehaviour on it that is disabled in the scene by default, the first time you enable it during play it is visible for one frame before OnEnable() runs on it, causing (for example) visual glitches if OnEnable() is used for setting up how it looks (spawned projectiles .. )

Disabling and enabling the object a second time does not have this issue.

This can be tested in client sim by creating a simple script that disables a child object in OnEnable(), and enables it in OnDisable(). Disable the main object then run, then hit pause, and enable the main object while paused, you will notice the first time you do it, the child object is visible.

In Monobehaviour (or sebsequent enablings) OnEnable() runs instantly even when paused.

Update() does not run on this frame (and it shouldn't)

This also effects instantiated objects.

fix: Run OnEnable() the instant the object is enabled, even the first time.