The following problem has been detected in Labview communication with Multisim:
When a new instance of Multisim is connected to Labview, and several operations are performed on it, the time it takes to do these operations increases progressively each time an operation is repeated. The time increases in each and every one of the operations that are performed on the open instance: measure, place components, etc ... The increase of time is significant since an operation that first time takes 0.5 seconds after several repetitions can take more than 5 seconds.
A temporary solution until you fix the problem is to close the connection with Multisim and re-instantiate a new connection.