Everything looks normal. You have a small offset of the Airspeed sensor of ca. 14 Pascal.
This results in an airspeed offset of nearly 5 m/s.
Example:
difference pressure = (air density / 2) * airspeed squared
or:
airspeed = square root (2 times difference pressure / density)
The nature of a square root dependency relates to significant changes especially near zero airspeed.
Put some numbers in the formula above results in
v = sqrt (2*14Pa/1.225gk/m**3) = 4.78 m/s
You can try to reduce the difference pressure sensor offset by let heat up the sensor and covering the Pitot-tube before the ground calibration. An offset drift of a few Pascals is common for this type of consumer grade sensors.
Hope this helps.