Top Engine RPM value does not match at the graph the actual engine RPM value

There are two possible causes:

Bad ratio or slip / tyre deformation: Check the actual engine RPM channel or OBDII RPM channel vs Calculated RPM to see if the actual RPM gets far from the calculated RPM graph, specially in the middle section (due to the higher torque)

Excessive filtering: Max recommended filter (LPF: Low Pass Filter) is 1/10 of the test duration (acceleration phase). For instance a test of 8 seconds (acceleration) should use a maximum filter of 0.8s. Tests which use excessive filtering (for instance LPF=4.0 sec) will show the power graph excessive rounded and will show lower HP and TQ results. This can also affect to the top calculated RPM values