i have a quick question for all. Assuming we have the 4 shards in ethereum and validators do their work validate transactions and assuming shard 3 has some problems and does not produce valid blocks, thus enter on change view protocol and stay behind from others. How can we guarantee that when the beacon chain changes the formation of all shards. Will shard 3 synchronize with the others? is there any existence of any global clock that says for example formation will be changed every one hour and all shards need to sync despite misconfiguration, or the beacon chain wait for shard 3 to catch up with other shards