The issue occurs when a monitor connected after an MST hub is unplugged, resulting in a null pointer dereference. This happens because `dc sink` is released immediately in `early unregister()` or `detect ctx()`, and committing a new state that refers to information stored in `dc sink` causes a null pointer dereference. The problem is resolved by removing a redundant checking condition and resetting `dsc aux` to NULL when the connector is disconnected.