Encoder Velocity Value Lags When Approaching Zero

[Marcus2024]

I am trying to record  linear velocity using an NI-9361 module and a single pulse encoder. When the encoder velocity decreases to zero the value becomes "stuck" at a random value and then immediately drops to zero after about 1/2 second.  I need to gather a deceleration time and cannot do so with the step. 

I have attempted to record RPM instead and have the same lag.