Target Airspeed changes when TRIM_ARPSD_CM isn't an integer value in m/s

I am running arduplane in SITL and noticed that in my tlog or the status tab in Mission Planner that my target airspeed constantly changes if the targetairspeed isn’t an integer value. For example, the target airspeed holds if TRIM_ARSPD_CM is set at 900, 1000, 1100, 1200, 1300, etc but constantly changes if it is set at 950, 1050, 1150, etc where in m/s it would be 9.5, 10.5, 11.5. I want to be able to have the targetairspeed be constant even if it is a float. Why does this happen and how could i fix this?