I updated to the recent 3.7.2-persistence-beta.1 SDK and this line of code returns null when it used to work fine. Object reference is not null and the object has a VRC Object Sync component.

MyGun.GetComponent<VRCObjectSync>().FlagDiscontinuity();

Edit: I cannot reproduce the issue in a clean project, even after an SDK upgrade. For some reason in the broken project null check on GetComponent<VRCObjectSync>() says it exists but when trying to call a function on it it returns null.

Edit 2: This is only happening in editor and client sim. Works in Build and test and when uploaded.