SPT peak search does not match to the RD map

[sinetech]

We generate a single tone sine wave by sinWaveGen in the data_generator.c. The peak location is at range bin 27, doppler bin 65 on RD map (in matlab, start ftom 1. It should be 26, 64 counting from 0 in c) from NCC outcome. However, the result from peaksearch SPT SDK is 19, 65, which shiftted 8 range bin left (please see the attached graph). I also printed out the range bin index and doppler bin index from the extractPeakData function in radar_processing.c by skipping CFAR (assumed that all the peaks are detected by CFAR). The result becomes 10, 64 (start from 0) which is another 8 range bin shift. 

What problem could it be? How can I correct it?

The SPT SDK version we use is "SWS32R41_Radar_SDK_0_9_0".