This is a feature that helps prevent having the same address selected on multiple throttles and creating unexpected operations. When you steal you are truly stealing control of the locomotive instead of sharing it.
When using a DT402 R2 throttle with an Advanced Command Station featuring expanded slots, each throttle ID is associated with the Loco Addresses it has selected. With a when you select a Loco that is selected on another throttle the second throttle will take ownership of the Loco and it will be deselected from the first throttle. By first throttle will display “StealZap” meaning it has deselected the loco because it has been stolen by another throttle. You always have the option to steal the loco back by selecting it again.
This feature only works when each DT402 R2 has a unique throttle ID and they are operating in expanded slots. If all throttles have the same ID stealing will work as it has in the past and two throttles can have control of a locomotive.
When using legacy throttles prior to the DT402 R2 stealing a locomotive will still result in the loco being selected and taking commands from two or more throttles.