If an agent misses a call when the system rings on them you can choose to have the agent automatically paused. This could be if the agent has left the computer but forgotten to pause themselves. If the setting is not enabled calls will continue to be sent to the agent and timing out which will result in a high amount of abandoned calls for that agent.

To avoid this, enable Auto Pause under the Queue Settings. The setting will then be standard for all agents in this queue: