When a networked custom event is sent with over 1kb of data to NetworkEventTarget.Self, the next networked custom event sent from that client does not send. Instead, the 1kb+ event is replayed, but to the new event target.

For example if I send a 1.5kb event MyEvent on BehaviourA to NetworkEventTarget.Self, then send an event OtherEvent on BehaviourB to NetworkEventTarget.Owner (other player), instead, the owner of BehaviourB will receive MyEvent on BehaviourA with 1.5kb of data.

Here is an example world where this can be seen: