SentriLock lockboxes are designed to record all agent activity when the showing agent has accessed the lockbox with their SentriLock card. When the showing agent accesses the lockbox using their card, the lockbox also uploads the last 3 agents that have accessed this lockbox to the showing agent's card.
When a showing agent renews their card, all of their information is posted in the SentriLock system along with the information for the last 3 showing agents that toured the property. This helps SentriLock collect the showing agent's information faster as showing agents do not always update their cards immediately. This would explain why you might see several different showings from different agents and different times all synced at the same time.